.. index:: ! gmtinfo ******* gmtinfo ******* .. only:: not man gmtinfo - Get information about data tables Synopsis -------- .. include:: common_SYN_OPTs.rst_ **gmtinfo** [ *table* ] [ |-A|\ **a**\ \|\ **f**\ \|\ **s** ] [ |-C| ] [ |-D|\ [*dx*\ [/*dy*\ ]] ] [ |-E|\ **L**\ \|\ **l**\ \|\ **H**\ \|\ **h**\ *col* ] [ |-F|\ [**i**\ \|\ **d**\ \|\ **t**\ ] ] [ |-I|\ [**p**\ \|\ **f**\ \|\ **s**]\ *dx*\ [/*dy*\ [/*dz*...] ] [ |-L| ] [ |-S|\ [**x**\ ][**y**] ] [ |-T|\ *dz*\ [\ **+c**\ *col*] ] [ |SYN_OPT-V| ] [ |SYN_OPT-bi| ] [ |SYN_OPT-di| ] [ |SYN_OPT-e| ] [ |SYN_OPT-f| ] [ |SYN_OPT-g| ] [ |SYN_OPT-h| ] [ |SYN_OPT-i| ] [ |SYN_OPT-o| ] [ **-r** ] [ |SYN_OPT-:| ] |No-spaces| Description ----------- **gmtinfo** reads its standard input [or from files] and finds the extreme values in each of the columns reported as slash-separated min/max pairs. It recognizes NaNs and will print warnings if the number of columns vary from record to record. The pairs can be split into two separate columns by using the **-C** option. As another option, **gmtinfo** can find the extent of data in the first two columns rounded up and down to the nearest multiple of the supplied increments given by **-I**. Such output will be in the text form **-R**\ *w/e/s/n*, which can be used directly on the command line for other modules (hence only *dx* and *dy* are needed). If **-C** is combined with **-I** then the output will be in column form and rounded up/down for as many columns as there are increments provided in **-I**. A similar option (**-T**) will provide a **-T**\ *zmin/zmax/dz* string for makecpt. Required Arguments ------------------ None. Optional Arguments ------------------ .. |Add_intables| unicode:: 0x20 .. just an invisible code .. include:: explain_intables.rst_ .. _-A: **-A**\ **a**\ \|\ **f**\ \|\ **s** Specify how the range should be reported. Choose **-Aa** for the range of all files combined, **-Af** to report the range for each file separately, and **-As** to report the range for each segment (in multisegment files) separately. [Default is **-Aa**]. .. _-C: **-C** Report the min/max values per column in separate columns [Default uses format]. When used, users may also use **-o** to limit which output columns should be reported [all]. .. _-D: **-D** Modifies results obtained by **-I** by shifting the region to better align with the center of the data. Optionally, append granularity for this shift [Default performs an exact shift]. .. _-E: **-EL**\ \|\ **l**\ \|\ **H**\ \|\ **h**\ *col* Returns the record whose column *col* contains the minimum (**l**) or maximum (**h**) value. Upper case (**L\|H**) works on absolute value of the data. In case of multiple matches, only the first record is returned. If *col* is not specified we default to the last column in the data. .. _-F: **-F**\ [**i**\ \|\ **d**\ \|\ **t**\ ] ] Returns the counts of various records depending on the appended mode: **i** returns a single record with the total number of tables, segments, data records, header records, and overall records. In contrast, **d** returns information for each segment in the virtual data set: *tbl_number, seg_number, n_rows, start_rec, stop_rec*. **t** does the same but honors the input table organization and thus resets *seg_number, start_rec, stop_rec* at the start of each new table. .. _-I: **-I**\ [**p**\ \|\ **f**\ \|\ **s**]\ *dx*\ [/*dy*\ [/*dz*...] Report the min/max of the first *n* columns to the nearest multiple of the provided increments (separate the *n* increments by slashes), and output results in the form **-R**\ *w/e/s/n* (unless **-C** is set). If only one increment is given we also use it for the second column (for backwards compatibility). To override this behavior, use **-Ip**\ *dx*. If the input *x*- and *y*-coordinates all have the same phase shift relative to the *dx* and *dy* increments then we use those phase shifts in determining the region, and you may use **-r** to switch from gridline-registration to pixel-registration. For irregular data both phase shifts are set to 0 and the **-r** is ignored. Use **-If**\ *dx*\ [/*dy*] to report an extended region optimized to give grid dimensions for fastest results in programs using FFTs. Use **-Is**\ *dx*\ [/*dy*] to report an extended region optimized to give grid dimensions for fastest results in programs like surface. If *dx* is given as - then the actual min/max of the input is given in the **-R** string. .. _-L: **-L** Determines common limits across tables (**-Af**) or segments (**-As**). If used with **-I** it will round inwards so that the resulting bounds lie within the actual data domain. .. _-S: **-S**\ [**x**][**y**] Add extra space for error bars. Useful together with **-I** option and when later plotting with :doc:`psxy` **-E**. **-Sx** leaves space for horizontal error bars using the values in third (2) column. **-Sy** leaves space for vertical error bars using the values in fourth (3) column. **-S** or **-Sxy** leaves space for both error bars using the values in third and fourth (2 and 3) columns. .. _-T: **-T**\ *dz*\ [\ **+c**\ *col*] Report the min/max of the first (0'th) column to the nearest multiple of *dz* and output this as the string **-T**\ *zmin/zmax/dz*. To use another column, append **+c**\ *col*. Cannot be used together with **-I**. .. _-V: .. |Add_-V| unicode:: 0x20 .. just an invisible code .. include:: explain_-V.rst_ .. |Add_-bi| replace:: [Default is 2 input columns]. .. include:: explain_-bi.rst_ .. |Add_-di| unicode:: 0x20 .. just an invisible code .. include:: explain_-di.rst_ .. |Add_-e| unicode:: 0x20 .. just an invisible code .. include:: explain_-e.rst_ .. |Add_-f| unicode:: 0x20 .. just an invisible code .. include:: explain_-f.rst_ .. |Add_-g| unicode:: 0x20 .. just an invisible code .. include:: explain_-g.rst_ .. |Add_-h| unicode:: 0x20 .. just an invisible code .. include:: explain_-h.rst_ .. include:: explain_-icols.rst_ .. include:: explain_-ocols.rst_ .. |Add_nodereg| unicode:: 0x20 .. just an invisible code .. include:: explain_nodereg.rst_ .. include:: explain_colon.rst_ .. include:: explain_help.rst_ .. include:: explain_precision.rst_ Examples -------- To find the extreme values in the file ship\_gravity.xygd: :: gmt info ship_gravity.xygd Output should look like :: ship_gravity.xygd: N = 6992 <326.125/334.684> <-28.0711/-8.6837> <-47.7/177.6> <0.6/3544.9> To find the extreme values in the file track.xy to the nearest 5 units but shifted to within 1 unit of the data center, and use this region to draw a line using :doc:`psxy`, run :: gmt psxy `gmt info -I5 -D1 track.xy` track.xy -Jx1 -B5 -P > track.ps To find the min and max values for each of the first 4 columns, but rounded to integers, and return the result individually for each data file, use :: gmt info profile_*.txt -C -I1/1/1/1 Given seven profiles with different start and stop positions, we want to find a range of positions, with increment of 5, that are common to all the profiles. We use :: gmt info profile_[123567].txt -L -I5 The file magprofs.txt contains a number of magnetic profiles stored as separate data segments. We need to know how many segments there are and use :: gmt info magprofs.txt -Fi Bugs ---- The **-I** option does not yet work properly with time series data (e.g., **-f**\ 0T). Thus, such variable intervals as months and years are not calculated. Instead, specify your interval in the same units as the current setting of :ref:`TIME_UNIT `. See Also -------- :doc:`gmt`, :doc:`gmtconvert`, :doc:`psxy`