Manual gmt

In addition, use x to skip n bytes anywhere in the record. For a mixed-type data record you can concatenate several [ n ] t combinations, separated by commas. You may append w to any of the items to force byte-swapping. Here, n is the number of each item in your binary file. Note that n may be larger than m , the number of columns that the GMT program requires to do its task. If n is not given then it defaults to m and all columns are assumed to be of the single specified type t [ d double , if not set].

Multiple segment files are allowed and the segment headers are assumed to be records where all the fields equal NaN. For native binary output, use the -bo option; see -bi for further details. Because of its meta data, reading netCDF tables i. When feeding netCDF tables to programs like plot , the program will automatically recognize the format and read whatever amount of columns are needed for that program.

To steer which columns are to be read, the user can append the suffix? No -bi option is needed in this case. Currently, netCDF tables can only be input, not output. For more information, see Chapter GMT file formats. However, there are occasionally the need to handle user data where missing data are represented by some unlikely data value such as Since GMT cannot guess that in your data set is a special value, you can use the -d option to have such values replaced with NaNs.

Similarly, should your GMT output need to conform to such a requirement you can replace all NaNs with the chosen nodata value. If only input or output should be affected, use -di or -do , respectably.

The -e option offers a built-in pattern scanner that will only pass records that match the given patterns or regular expressions. The test can also be inverted to only pass data records that do not match the pattern. The test is not applied to header or segment headers.

When map projections are not required we must explicitly state what kind of data each input or output column contains. This is accomplished with the -f option.

Following an optional i for input only or o for output only , we append a text string with information about each column or range of columns separated by commas. Each string starts with the column number 0 is first column followed by either x longitude , y latitude , T absolute calendar time or t relative time. If several consecutive columns have the same format you may specify a range of columns rather than a single column, i.

For example, if our input file has geographic coordinates latitude, longitude with absolute calendar coordinates in the columns 3 and 4, we would specify fi 0 y ,1 x ,3—4 T. All other columns are assumed to have the default, floating point format and need not be set individually. The shorthand -f [ i o ] g means -f [ i o ]0x,1y i.

A special use of -f is to select -fp [ unit ], which requires -J and lets you use projected map coordinates e. Such coordinates are automatically inverted to longitude, latitude during the data import. Optionally, append a length unit see Table distunits [meter]. For more information, see Sections Input data formats and Output data formats. GMT has several mechanisms that can determine line segmentation. Typically, data segments are separated by multiple segment header records see Chapter GMT file formats.

However, if key data columns contain a NaN we may also use that information to break lines into multiple segments. If you wish such records to indicate a segment boundary then set this parameter to pass. Finally, you may wish to indicate gaps based on the data values themselves. Gaps can be based on excessive jumps in the x - or y -coordinates -gx or -gy , or on the distance between points -gd. Append the gap distance and optionally a unit for actual distances. For geographic data the optional unit may be arc d egree, m inute, and s econd, or m e ter [Default], f eet, k ilometer, M iles, or n autical miles.

For programs that map data to map coordinates you can optionally specify these criteria to apply to the projected coordinates by using upper-case -gX , -gY or -gD. If there are more than one header record you must specify the number after the -h option, e.

Note that blank lines and records that start with the character are automatically considered header records and skipped. The default number of such header records if -h is used is one of the many parameters in the gmt. Normally, programs that both read and write tables will output the header records that are found on input. Use -hi to suppress the writing of header records. You can use the -h options modifiers to to tell programs to output extra header records for titles, remarks or column names identifying each data column.

When -b is used to indicate binary data the -h takes on a slightly different meaning. The -i columns option allows you to specify which input file physical data columns to use and in what order.

By default, GMT will read all the data columns in the file, starting with the first column 0. Using -i modifies that process and reads in a logical record based on columns from the physical record. For instance, to use the 4th, 7th, and 3rd data column as the required x,y,z to blockmean you would specify -i 3,6,2 since 0 is the first column.

The chosen data columns will be used as is. Optionally, you can specify that input columns should be transformed according to a linear or logarithmic conversion. Next, we may scale the result by the given scale [1]. Finally, we add in the specified offset [0]. If you want the trailing text to remain part of your subset logical record then also select the special column by requesting column t , otherwise we ignore trailing text.

Finally, to use the entire numerical record and ignoring trailing text, use -in. The physical, logical input and output record in GMT. Here, we are reading a file with 5 numerical columns plus some free-form text at the end. Our module here plot will be used to plot circles at the given locations but we want to assign color based on the depth column which we need to convert from meters to km and symbol size based on the mag column but we want to scale the magnitude by 0.

We use -i to pull in the desired columns in the required order and apply the scaling, resulting in a logical input record with 4 columns. The -f option can be used to specify column types in the logical record if it is not clear from the data themselves such as when reading a binary file. Finally, if a module needs to write out only a portion of the current logical record then you may use the corresponding -o option to select desired columns, including the trailing text column t.

Note that these column numbers now refer to the logical record, not the physical, since after reading the data there is no physical record, only the logical record in memory. The -n type option controls parameters used for 2-D grids resampling. You can select the type of spline used -nb for B-spline smoothing, -nc for bicubic [Default], -nl for bilinear, or -nn for nearest-node value. By default, boundary conditions are set according to the grid type and extent.

Append x or y to only apply the condition in one dimension. A threshold of 1. The -o columns option allows you to specify which columns to write on output and in what order. By default, GMT will write all the data columns produced by the program. Using -o modifies that process.

For instance, to write just the 4th and 2nd data column to the output you would use -o 3,1 since 0 is the first column. You can also use a column more than once, e. Finally, if your logical record in memory contains trailing text then you can include that by including the special column t to your selections.

The text is always written after any numerical columns. Note that if you wanted to scale or shift the output values you need to do so during reading, using the -i option. To output all numerical columns and ignoring trailing text, use -on. All plotting programs that normally produce a flat, two-dimensional illustration can be told to view this flat illustration from a particular vantage point, resulting in a perspective view.

When -p is used in consort with -Jz or -JZ , a third value can be appended which indicates at which z -level all 2-D material, like the plot frame, is plotted in perspective [Default is at the bottom of the z-axis]. When -p is used without any further arguments, the values from the last use of -p in a previous GMT command will be used.

Alternatively, you can perform a simple rotation about the z-axis by just giving the rotation angle. All 2-D grids in GMT have their nodes organized in one of two ways, known as gridline - and pixel - registration. The GMT default is gridline registration; programs that allow for the creation of grids can use the -r option to select pixel registration instead.

Most observed data tend to be in gridline registration while processed data sometime may be distributed in pixel registration. While you may convert between the two registrations this conversion looses the Nyquist frequency and dampens the other high frequencies. It is best to avoid any registration conversion if you can help it.

Planning ahead may be important. In this registration, the nodes are centered on the grid line intersections and the data points represent the average value in a cell of dimensions centered on each node left side of Figure Grid registration. In the case of grid line registration the number of nodes are related to region and grid spacing by. Here, the nodes are centered in the grid cells, i. In the case of pixel registration the number of nodes are related to region and grid spacing by.

Gridline- and pixel-registration of data nodes. The red shade indicates the areas represented by the value at the node solid circle. We can use this option to suppress output for records whose z -value equals NaN by default we output all records. Alternatively, append r to reverse the suppression, i. Use -sa to suppress output records where one or more fields and not necessarily z equal NaN.

Finally, you can supply a comma-separated list of all columns or column ranges to consider for this NaN test. While the PostScript language does not support transparency, PDF does, and via PostScript extensions one can manipulate the transparency levels of objects. The -t option allows you to change the transparency level for the current overlay by appending a percentage in the 0— range; the default is 0, or opaque.

Transparency may also be controlled on a feature by feature basis when setting color or fill see section Specifying area fill attributes.

For geographical data, the first column is expected to contain longitudes and the second to contain latitudes. To reverse this expectation you must apply the -: option. Optionally, append i or o to restrict the effect to input or output only. Note that command line arguments that may take geographic coordinates e. Also, geographical grids are expected to have the longitude as first minor dimension.

For example, if a basemap was created with an oblique Mercator projection, specified as. In contrast, note that -J by itself will pick the most recently used projection. Previous commands are maintained in the file gmt. This is handy if you create separate directories for separate projects since chances are that data manipulations and plotting for each project will share many of the same options.

Note that an option spelled out on the command line will always override the previous entry in the gmt. The only guarantee is that the file will not be clobbered since GMT uses advisory file locking. The uncertainty in processing order makes the use of shorthands in pipes unreliable.

We therefore recommend that you only use shorthands in single process command lines, and spell out the full command option when using chains of commands connected with pipes.

The history can be cleared by running gmt clear history. Each program carries a usage message. If you enter the program name without any arguments, the program will write the complete usage message to standard error your screen, unless you redirect it.

This message explains in detail what all the valid arguments are. If you enter the program name followed by a hyphen - only you will get a shorter version which only shows the command line syntax and no detailed explanations.

If you incorrectly specify an option or omit a required option, the program will produce syntax errors and explain what the correct syntax for these options should be. If an error occurs during the running of a program, the program will in some cases recognize this and give you an error message. Usually this will also terminate the run. The error messages generally begin with the name of the program in which the error occurred; if you have several programs piped together this tells you where the trouble is.

Most of the programs which expect table data input can read either standard input or input in one or several files. These programs will try to read stdin unless you type the filename s on the command line without the above hyphens. If the program sees a hyphen, it reads the next character as an instruction; if an argument begins without a hyphen, it tries to open this argument as a filename.

This feature allows you to connect programs with pipes if you like. To give numerous input files you can either list them all file1. This allows GMT modules to obtain the input file names from filelist. If your input is ASCII and has one or more header records that do not begin with , you must use the -h option see Section Header data records: The -h option. ASCII files may in many cases also contain segment-headers separating data segments. For binary table data the -h option may specify how many bytes should be skipped before the data section is reached.

Binary files may also contain segment-headers separating data segments. These segment-headers are simply data records whose fields are all set to NaN; see Chapter GMT file formats for complete documentation. If filenames are given for reading, GMT programs will first look for them in the current directory. They may be set by the user to point to directories that contain data sets of general use, thus eliminating the need to specify a full path to these files.

See directory parameters for details. Program output is always written to the current directory unless a full path has been specified. The 1x1 degree tiles red for which SRTM 1 and 3 arc second data are available. Verbose will write to standard error information about the progress of the operation you are running.

Verbose reports things such as counts of points read, names of data files processed, convergence of iterative solutions, and the like. Since these messages are written to stderr , the verbose talk remains separate from your data output. You may optionally choose among five models of verbosity ; each mode adds more messages with an increasing level of details.

The modes are. The verbosity is cumulative, i. Most programs write their results, including PostScript plots, to standard output.

The exceptions are those which may create binary netCDF grid files such as surface due to the design of netCDF a filename must be provided; however, alternative binary output formats allowing piping are available; see Section Grid file format specifications. Most operating systems let you can redirect standard output to a file or pipe it into another process. Error messages, usage messages, and verbose comments are written to standard error in all cases.

You can usually redirect standard error as well, if you want to create a log file of what you are doing. The syntax for redirection differ among the main shells Bash and C-shell and is a bit limited in DOS. Most of the time, GMT will know what kind of x and y coordinates it is reading because you have selected a particular coordinate transformation or map projection.

However, there may be times when you must explicitly specify what you are providing as input using the -f switch. When binary input data are expected -bi you must specify exactly the format of the records. However, for ASCII input there are numerous ways to encode data coordinates which may be separated by white-space or commas. Valid input data are generally of the same form as the arguments to the -R option see Section Data domain or map region: The -R option , with additional flexibility for calendar data.

Geographical coordinates, for example, can be given in decimal degrees e. With -fp you may even supply projected data like UTM coordinates. A complete description of possible formats is given in the gmt. The clock string is more standardized but issues like or hour clocks complicate matters as well as the presence or absence of delimiters between fields.

GMT programs that require a map projection argument will implicitly know what kind of data to expect, and the input processing is done accordingly. However, some programs that simply report on minimum and maximum values or just do a reformatting of the data will in general not know what to expect, and furthermore there is no way for the programs to know what kind of data other columns beyond the leading x and y columns contain. In such instances we must explicitly tell GMT that we are feeding it data in the specific geographic or calendar formats floating point data are assumed by default.

We specify the data type via the -f option which sets both input and output formats; use -fi and -fo to set input and output separately. For instance, to specify that the the first two columns are longitude and latitude, and that the third column e.

For more details, see the man page for the program you need to use. In the latter case the issue of formatting becomes important. GMT provides extensive machinery for allowing just about any imaginable format to be used on output. Analogous to the processing of input data, several templates guide the formatting process. PostScript is a command language for driving graphics devices such as laser printers.

It is ASCII text which you can read and edit as you wish assuming you have some knowledge of the syntax. We prefer this to binary metafile plot systems since such files cannot easily be modified after they have been created.

GMT programs also write many comments to the plot file which make it easier for users to orient themselves should they need to edit the file e. See the manual pages for PSL syntax. Although GMT programs can create very individualized plot code, there will always be cases not covered by these programs. Some knowledge of PostScript will enable the user to add such features directly into the plot file.

A pen in GMT has three attributes: width , color , and style. Most programs will accept pen attributes in the form of an option argument, with commas separating the given attributes, e. The style attribute controls the appearance of the line.

The lengths of dots and dashes are scaled relative to the pen width dots has a length that equals the pen width while dashes are 8 times as long; gaps between segments are 4 times the pen width. For more detailed attributes including exact dimensions you may specify string : offset , where string is a series of numbers separated by underscores. These numbers represent a pattern by indicating the length of line segments and the gap between segments. The offset phase-shifts the pattern from the beginning the line.

For example, if you want a yellow line of width 0. Just as with pen width, the default style units are points, but can also be explicitly specified in cm, inch, or points see width discussion above. Table penex contains additional examples of pen specifications suitable for, say, plot. In addition to these pen settings there are several PostScript settings that can affect the appearance of lines. They determine how a line segment ending is rendered, be it at the termination of a solid line or at the end of all dashed line segments making up a line, and how a straight lines of finite thickness should behave when joined at a common point.

By default, line segments have rectangular ends, but this can change to give rounded ends. This can be used to created circular dotted lines, and by manipulating the phase shift in the style attribute and plotting the same line twice one can even alternate the color of adjacent items.

Figure Line appearance shows various lines made in this fashion. See the gmt. A line is drawn with the texture provided by the chosen pen Specifying pen attributes.

However, depending on the module, a line also may have other attributes that can be changed in some modules. Given as modifiers to a pen specification, one or more modifiers may be appended to a pen specification. The line attribute modifiers are:. Note that we also prescribed the line offsets in addition to the symbol endings.

Many plotting programs will allow the user to draw filled polygons or symbols. The fill specification may take two forms:. Due to PostScript implementation limitations the raster images used with -G must be less than x pixels in size; for larger images see image.

Note that under PostScript Level 1 the patterns are filled by using the polygon as a clip path. Complex clip paths may require more memory than the PostScript interpreter has been assigned. There is therefore the possibility that some PostScript interpreters especially those supplied with older laserwriters will run out of memory and abort.

Should that occur we recommend that you use a regular gray-shade fill instead of the patterns. Installing more memory in your printer may or may not solve the problem! Table fillex contains a few examples of fill specifications.

However, some programs, like text may wish to have this information passed directly. A font is specified by a comma-delimited attribute list of size , fonttype and fill , each of which is optional. The size is the font size usually in points but c , i or p can be added to indicate a specific unit. The fonttype is the name case sensitive! If any of the attributes is omitted their default or previous setting will be retained.

The PostScript language has no built-in mechanism for transparency. However, PostScript extensions make it possible to request transparency, and tools that can render such extensions will produce transparency effects. We specify transparency in percent: 0 is opaque [Default] while is fully transparent i. As noted in section Layer PDF transparency: The -t option , we can control transparency on a layer-by-layer basis using the -t option.

However, we may also set transparency as an attribute of stroke or fill including for fonts settings. Here, transparency is requested by appending transparency to colors or pattern fills. For more information, see for instance search online for the Adobe pdfmark Reference Manual. Most printers and many PostScript viewers can neither print nor show transparency.

They will simply ignore your attempt to create transparency and will plot any material as opaque. Many text labels placed on maps are part of the standard basemap machinery e. However, when you wish to add extra text to a plot in locations of your choice you will need to understand how we reference text to locations on the map. Figure Text justification discusses the various ways to do this. Text strings are placed on maps by associating an anchor point on the string with a reference point on the map.

Nine anchor points relative to any text string may be specified by combining any of three letter codes for horizontal L eft, C enter, R ight and vertical T op, M iddle, B ottom alignments.

Notice how the anchor points refers to the text baseline and do not change for text whose letters extend below the baseline. The concept of anchor points extends to entire text paragraphs that you may want to typeset with text. A related point involves the footprint of the text and any background panel on the map. We determine the bounding box for any text string, but very often we wish to extend this box outwards to allow for some clearance between the text and the space surrounding it.

Programs that allows for such clearance will let you specify offsets dx and dy that is used to enlarge the bounding box, as illustrated in Figure Text clearance. The bounding box of any text string can be enlarged by specifying the adjustments dx and dy in the horizontal and vertical dimension.

The shape of the bounding box can be modified as well, including rounded or convex rectangles. Here we have chosen a rounded rectangle, requiring the additional specification of a corner radius, r. Several programs need to relate user data to colors, shades, or even patterns. For instance, programs that read 2-D gridded data sets and create colored images or shaded reliefs need to be told what colors to use and over what z -range each color applies.

Other programs may need to associate a user value with a color to be applied to a symbol, line, or polygon. This is the purpose of the color palette table CPT.

For most applications, you will simply create a CPT using the tool makecpt which will take an existing dynamic master color table and stretch it to fit your chosen data range, or use grd2cpt to build a CPT based on the data distribution in one or more given grid files. However, in rare situations you may need to make a CPT by hand or using text tools like awk or perl.

Color palette tables CPT comes in two flavors: 1 Those designed to work with categorical data e. In both cases the fill information follows the format given in Section Specifying area fill attributes. Since GMT supports several coordinate systems for color specification, many master or user CPTs will contain the special comment. Categorical data are information on which normal numerical operations are not defined. As an example, consider various land classifications desert, forest, glacier, etc.

For such data a special format of the CPTs are provided. Here, each category is assigned a unique key, a color or pattern, and an optional label usually the category name marked by a leading semi-colon. Keys must be monotonically increasing but do not need to be consecutive. The format is. For usage with points, lines, and polygons, the keys may be text single words , and then GMT will use strings to find the corresponding Fill value.

If any of your keys are called B, F, or N you must escape them with a leading backslash to avoid confusion with the flags for background, foreground and NaN colors. The Fill information follows the format given in Section Specifying area fill attributes. For categorical data, background color or foreground color do not apply. The not-a-number NaN color for key -values not found or blank is defined in the gmt.

Suitable for continuous data types and allowing for color interpolations, the format of the regular CPTs is:. If patterns are used then the second max pattern must be set to -. The optional flag A is used to indicate annotation of the color scale when plotted using colorbar.

The optional flag A may be L , U , or B to select annotation of the lower, upper, or both limits of the particular z -slice, respectively. However, the standard -B option can be used by colorbar to affect annotation and ticking of color scales. Just as other GMT programs, the stride can be omitted to determine the annotation and tick interval automatically e. The optional semicolon followed by a text label will make colorbar , when used with the -L option, place the supplied label instead of formatted z -values.

If you prefer the HSV system, set the gmt. A few programs i. You must specify the pattern as in Section Specifying area fill attributes no leading -G of course , and only the first pattern for low z is used we cannot interpolate between patterns.

Finally, some programs let you skip features whose z -slice in the CPT file has gray-shades set to -. As an example, consider. Some programs like grdimage and grdview apply artificial illumination to achieve shaded relief maps. An intensity of zero leaves the color unchanged. Higher values will brighten the color, lower values will darken it, all without changing the original hue of the color see Chapter Color Space: The Final Frontier for more details.

Such intensity files can be derived from the data grid using grdgradient and modified with grdhisteq , but could equally well be a separate data set. Similarly, one could portray magnetic anomalies superimposed on topography by using the former for colors and the latter for shading. This means they have several special properties that modify the behavior of programs that use them.

The hinge value is specified via the special comment. CPTs without a hinge are instead normalized with z -values from 0 to 1. In contrast, CPTs without a natural range are instead stretched to fit the range of the data in question e. These tools can also read static CPTs where the new range must be specified or computed from data , reversing the order of colors, and even isolating a section of an incoming CPT. Here, makecpt can be told the range of compute it from data tables while grd2cpt can derive the range from one or more grids.

Because of the hinge, the two sides of the CPT will be stretched separately to honor the desired range while utilizing the full color range.

Any color table you produce can be turned into a cyclic or wrapped color table. This is performed by adding the -Ww option when running makecpt or grd2cpt. This option simply adds the special comment. This means that the fore- and back-ground colors can never be activated. Wrapped color tables are useful for highlighting small changes. Cyclic color bars are indicated by a cycle symbol on the left side of the bar. The tools makecpt and grd2cpt allow several types of transformations to take place:.

The order of these transformations is important. For instance, if -Iz is given then all other z -values need to be referred to the new sign convention. For most applications only the last transformation is needed. Examples of two user CPTs for the range One left extracted a subset of the master before scaling while the other right used the entire range.

GMT supports plotting vectors in various forms. A vector is one of many symbols that may be plotted by plot and plot3d , is the main feature in grdvector , and is indirectly used by other programs. All vectors plotted by GMT consist of two separate parts: The vector line controlled by the chosen pen attributes and the optional vector head s controlled by the chosen fill. We distinguish between three types of vectors:. Examples of Cartesian left , circular middle , and geo-vectors right for different attribute specifications.

Note that both full and half arrow-heads can be specified, as well as no head at all. There are numerous attributes you can modify, including how the vector should be justified relative to the given point beginning, center, or end , where heads if any should be placed, if the head should just be the left or right half, if the vector attributes should shrink for vectors whose length are less than a given cutoff length, and the size and shape of the head.

These attributes are detailed further in the relevant manual pages. Examples of different vector heads and attributes. Other vector heads are the circle c , the terminal line t , the arrow fin i and the plain head A and tail I ; the last two are line-drawings only and cannot be filled. For annotation labels or text strings plotted with text , GMT provides several escape sequences that allow the user to temporarily switch to the symbol font, turn on sub- or superscript, etc. The escape sequences recognized in GMT are listed in Table escape.

Only one level of sub- or superscript is supported. Note that under Windows the percent symbol indicates a batch variable, hence you must use two percent-signs for each one required in the escape sequence for font switching. Shorthand notation for a few special European characters has also been added for others you must use the full octal code :.

PostScript fonts used in GMT may be re-encoded to include several accented characters used in many European languages. Only the special characters belonging to a particular encoding will be available. Many characters not directly available by using single octal codes may be constructed with the composite character mechanism!.

The option in text to draw a rectangle surrounding the text will not work for strings with escape sequences. Apart from visualizing your data sets, GMT maps can also be embellished in several ways. The 9 embellishments currently available are.

Each of these features share a common system for specifying the location on the plot where the feature will be placed. They also share a common way for specifying the placement of a rectangular panel behind the feature to provide a uniform background, for instance. The placement of a map feature here represented by a green rectangle in relation to the underlying map. The nine named reference points blue circles on the map perimeter and center can be used to specify a location.

Using the same system of nine points on the map feature cyan circles we select one of these as our anchor point here TL, indicated by the orange square. The feature is then placed such that its adjusted anchor point matches the reference point. Placing a feature on the map means selecting a reference point somewhere on the map, an anchor point somewhere on the feature, and then positioning the feature so that the two points overlap. This form guarantees a rectangular map even though lines of equal longitude and latitude are not straight lines.

This will copy the domain settings found for the grid in specified file. Note that depending on the nature of the calling module, this mechanism will also set grid spacing and possibly the grid registration see Grid registration: The -r option. This indirectly supplies the region by consulting the DCW Digital Chart of the World database and derives the bounding regions for one or more countries given by the codes.

Simply append one or more comma-separated countries using the two-character ISO alpha-2 convention. To select a state within a country if available , append. TX for Texas. The following modifiers can be appended:.

This method can be used when creating grids. This is not used for -p without -Jz , in which case a perspective view of the place is plotted with no third dimension. Under modern mode, and for plotting modules only, you can automatically determine the region from the data used. You can either get the exact area using -Re [Default if no -R is given] or a slightly larger area sensibly rounded outwards to the next multiple of increments that depend on the data range using -Ra.

In case of perspective view -p , a z-range zmin , zmax can be appended to indicate the third dimension. This needs to be done only when using the -Jz option, not when using only the -p option. In the latter case a perspective view of the plane is plotted, with no third dimension. Draw GMT time stamp logo on plot. The -U option draws the GMT system time stamp on the plot.

The following modifiers are supported:. The time string will be in the locale set by the environment variable TZ generally local time. Select verbosity level [ w ]. The -V option controls the verbosity mode, which determines which messages are sent to standard error. Choose among 7 levels of verbosity; each level adds more messages:. Shift plot origin. The -X and -Y options shift the plot origin relative to the current origin by xshift , yshift.

Optionally, append the length unit c , i , or p. Subsequent overlays will be co-registered with the previous plot unless the origin is shifted using these options. The following modifiers are supported [default is r ]:. Prepend c to center the plot on the center of the paper optionally add a shift. When -X or -Y are used without any further arguments, the values from the last use of that option in a previous GMT command will be used. Note that -X and -Y can also access the previous plot bounding box dimensions w and h and construct offsets that involves them.

Note : the previous plot bounding box refers to the last object plotted, which may be an image, logo, legend, colorbar, etc. GMT relies on external tools to translate geospatial files such as shapefiles into a format we can read. For this to be useful we need a mechanism to associate certain metadata values with required input and output columns expected by GMT programs.

The given aspatial field thus replaces any other value already set. Note : If no aspatial attributes are needed then the -a option is not needed — GMT will still process and read such data files. You can also associate aspatial fields with other settings such as labels, fill colors, pens, and values for looking-up colors by letting the col value be one of D for distance , G for fill , I for ID , L for label , T for text , W for pen , or Z for value. This works analogously to how standard multi-segment files can pass such options via its segment headers See the cookbook chapter GMT File Formats.

As for input, you can also use the special col entries of D for distance , G for fill , I for ID , L for label , T for text , W for pen , or Z for value to have values stored as options in segment headers be used as the source for the named aspatial field. The type will be set automatically for these special col entries.

Select native binary record format for primary table input. The record is one or more groups with format [ ncols ][ type ][ w ], where ncols is the number of consecutive data columns of given type and type must be one of:.

Force byte-swapping of a group by appending w at the end of the group. For records with mixed types, append additional comma-separated groups no space between groups.

The cumulative number of ncols may exceed the columns actually needed by the program. If ncols is not specified we assume that type applies to all columns and that ncols is implied by the expectation of the program. When using native binary data the user must be aware of the fact that GMT has no way of determining the actual number of columns in the file.

Native binary files may have a header section, where the -h option can be used to skip the first n bytes. If the input file is netCDF, no -b is needed; simply append?

Here is an example that writes a binary file and reads it back with the first column 4 byte float, the second column 8 byte int, and the third column 8 byte double.

Select native binary format for table output. The record must be one or more groups with format [ ncols ][ type ][ w ], where ncols is the number of consecutive data columns of given type and type must be one of c , u , h , H , i , I , l , L , f , or d [Default] see -bi types for descriptions.

For a mixed-type output record, append additional comma-separated groups no space between groups The following modifiers are supported:.

If ncols is not specified we assume that type applies to all columns and that ncols is implied by the default output of the program. Note : NetCDF file output is not supported. The -c option is only allowed when in subplot mode. Note : row , col , and index all start at 0. However, user data may occasionally denote missing data with an unlikely value e.

Since GMT cannot guess this special missing data value, you can use the -d option to have such values replaced with NaNs. Similarly, the -d option can replace all NaNs with the chosed nodata value should the GMT output need to conform to such a requirement. For input only, use -di nodata to examine all input columns after the first two.

If any item equals nodata , the value is interpreted as a missing data item and is substituted with the value NaN. For output only, use -do nodata to examine all output columns. If any item equals NaN, the NaN value is substituted with the chosen missing data value nodata. The -e option offers a built-in pattern scanner that will only pass records that match the given pattern or regular expressions, whereas modules that read ASCII tables will normally process all the data records that are read.

The test is not applied to header or segment headers. For matching data records against extended regular expressions , please enclose the expression in slashes.

Append i for case-insensitive matching. The -f option specifies what kind of data each input or output column contains when map projections are not required. Optionally, append i or o to make this apply only to input or output, respectively [Default applies to both].

Append a text string with information about each column or range of columns separated by commas. If several consecutive columns have the same format you may specify a range of columns rather than a single column. Column ranges must be given in the format start [: inc ]: stop , where inc defaults to 1 if not specified. For example, if our input file has geographic coordinates latitude, longitude with absolute calendar coordinates in the columns 3 and 4, we would specify fi 0 y ,1 x , T.

All other columns are assumed to have the default f loating point format and need not be set individually. Note : You can also indicate that all items from the given column and to the end of the record should be considered trailing text by giving the code s for string.

Only the last group may set s. Three shorthand options for common selections are available. The shorthand -f [ i o ] g means -f [ i o ]0x,1y i. A special use of -f is to select -fp [ unit ], which requires -J -R and lets you use projected map coordinates e.

Such coordinates are automatically inverted to longitude, latitude during the data import. Optionally, append a length unit see table distance units [default is meter]. For more information, see Sections Input data formats and Output data formats.

The -g option is used to detect gaps based on one or more criteria. Repeat the option to specify multiple criteria. A criterion is specified using one of the x y z d X Y D directives.

The upper-case directives specify that the criterion should be applied to the projected coordinates for modules that map data to map coordinates. For geographic data x y d , the unit may be arc d egree , m inute , and s econd , or m e ter , f eet , k ilometer , M iles , or n autical miles [Default is m e ter ]. Default imposes breaks based on the absolute value of the difference between the current and previous value.

Specify that the primary input file s has n header record s. Use -hi if only the primary input data should have header records [Default will write out header records if the input data have them]. For output you may control the writing of header records using -h [ o ] and the optional modifiers:. Note : Blank lines and lines starting with are always skipped. With -h in effect the first n records are taken verbatim as headers and not skipped even if any is starting with.

Note : If used with native binary data using -b we interpret n to instead mean the number of bytes to skip on input or pad on output. The -i option allows you to specify which input file physical data columns to use and in what order. Specify individual columns or column ranges in the format start [: inc ]: stop , where inc defaults to 1 if not specified, separated by commas [Default reads all columns in order, starting with the first column i. Columns can be repeated. The chosen data columns will be used as given and columns not listed will be skipped.

Optionally, append one of the following modifiers to any column or column range to transform the input columns:. To read from a given column until the end of the record, leave off stop when specifying the column range. To only ingest a single word from the trailing text, append the word number first word is 0. Share this page facebook twitter linkedin pinterest weibo qq douban. The Rolex user guides provide owners with all steps to properly use their watches.

Got one to sell? Model: steel. Material1, Bezel2, Dial3. Configure your modelReset your configuration. Add to wishlist. Part of the Rolex Professional Watch Collection, it was initially a collaboration between Rolex and Pan Am Airways for use by their pilots and navigators on long haul flights.

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