pshistogram¶
pshistogram - Calculate and plot histograms
Synopsis¶
pshistogram [ table ] -Jx|Xparameters -Wbin_width[+l|h|b] [ -A ] [ -B[p|s]parameters ] [ -Ccpt ] [ -D[+b][+ffont][+ooff][+r] ] [ -F ] [ -Gfill ] [ -Jz|Zparameters ] [ -I[o|O] ] [ -K ] [ -Lpen ] [ -N[mode][+ppen] ] [ -O ] [ -P ] [ -Q ] [ -Rregion ] [ -S ] [ -U[stamp] ] [ -V[level] ] [ -Xx_offset ] [ -Yy_offset ] [ -Z[type][+w] ] [ -bibinary ] [ -dinodata ] [ -eregexp ] [ -fflags ] [ -hheaders ] [ -iflags ] [ -pflags ] [ -ttransp ]
Note: No space is allowed between the option flag and the associated arguments.
Description¶
pshistogram reads file [or standard input] and examines the first data column (or use -i) to calculate histogram parameters based on the bin-width provided. Using these parameters, scaling, and optional range parameters it will generate PostScript code that plots a histogram. A cumulative histogram may also be specified.
Required Arguments¶
- -Jx
- xscale[/yscale] (Linear scale(s) in distance unit/data unit).
- -Wbin_width[+l|h|b]
- Sets the bin width used for histogram calculations. The modifiers specify the handling of extreme values that fall outside the range set by -R. By default these values are ignored. Use +b to let these values be included in the first or last bins. To only include extreme values below first bin into the first bin, use +l, and to only include extreme values above the last bin into that last bin, use +h.
Optional Arguments¶
- table
- One or more ASCII (or binary, see -bi[ncols][type]) data table file(s) holding a number of data columns. If no tables are given then we read from standard input.
- -A
- Plot the histogram horizontally from x = 0 [Default is vertically from y = 0]. The plot dimensions remain the same, but the two axes are flipped.
- -B[p|s]parameters (more …)
- Set map boundary frame and axes attributes.
- -Ccpt
- Give a CPT. The mid x-value for each bar is used to look-up the bar color.
- -D[+b][+ffont][+ooff][+r]
- Annotate each bar with the count it represents. Append any of the following modifiers: Use +b to place the labels beneath the bars instead of above; use +f to change to another font than the default annotation font; use +o to change the offset between bar and label [6p]; use +r to rotate the labels from horizontal to vertical.
- -F
- Center bin on each value. [Default is left edge].
- -Gfill
- Select filling of bars [Default is no fill].
- -I[o|O]
- Inquire about min/max x and y after binning. The xmin xmax ymin ymax is output; no plotting is done. Append o to output an ASCII table of the resulting x,y data instead. Upper case O will output all x,y bin data even when y == 0.
- -Jz|Zparameters (more …)
- Set z-axis scaling; same syntax as -Jx.
- -K (more …)
- Do not finalize the PostScript plot.
- -Lpen
- Draw bar outline using the specified pen thickness. [Default is no outline].
- -N[mode][+ppen]
Draw the equivalent normal distribution; append desired pen [0.5p,black]. The mode selects which central location and scale to use:
- 0 = mean and standard deviation [Default];
- 1 = median and L1 scale;
- 2 = LMS mode and scale.
The -N option may be repeated to draw several of these curves.
- -O (more …)
- Append to existing PostScript plot.
- -P (more …)
- Select “Portrait” plot orientation.
- -Q
- Draw a cumulative histogram.
- -Rxmin/xmax/ymin/ymax[+r][+uunit] (more …)
- Specify the region of interest.
For perspective view p, optionally append /zmin/zmax. (more …) If not given, pshistogram will automatically find reasonable values for the region.
- -S
- Draws a stairs-step diagram which does not include the internal bars of the default histogram.
- -U[[just]/dx/dy/][c|label] (more …)
- Draw GMT time stamp logo on plot.
- -V[level] (more …)
- Select verbosity level [c].
-X[a|c|f|r][x-shift[u]]
- -Y[a|c|f|r][y-shift[u]] (more …)
- Shift plot origin.
- -Z[type][+w]
Choose between 6 types of histograms:
- 0 = counts [Default]
- 1 = frequency_percent
- 2 = log (1.0 + count)
- 3 = log (1.0 + frequency_percent)
- 4 = log10 (1.0 + count)
- 5 = log10 (1.0 + frequency_percent).
To use weights provided as a second data column instead of pure counts, append +w.
- -bi[ncols][t] (more …)
- Select native binary input. [Default is 2 input columns].
- -dinodata (more …)
- Replace input columns that equal nodata with NaN.
- -e[~]”pattern” | -e[~]/regexp/[i] (more …)
- Only accept data records that match the given pattern.
- -f[i|o]colinfo (more …)
- Specify data types of input and/or output columns.
- -h[i|o][n][+c][+d][+rremark][+rtitle] (more …)
- Skip or produce header record(s).
- -icols[+l][+sscale][+ooffset][,…] (more …)
- Select input columns and transformations (0 is first column).
- -p[x|y|z]azim[/elev[/zlevel]][+wlon0/lat0[/z0]][+vx0/y0] (more …)
- Select perspective view.
- -t[transp] (more …)
- Set PDF transparency level in percent.
- -^ or just -
- Print a short message about the syntax of the command, then exits (NOTE: on Windows just use -).
- -+ or just +
- Print an extensive usage (help) message, including the explanation of any module-specific option (but not the GMT common options), then exits.
- -? or no arguments
- Print a complete usage (help) message, including the explanation of all options, then exits.
Examples¶
To draw a histogram of the data v3206.t containing seafloor depths, using a 250 meter bin width, center bars, and draw bar outline, use:
gmt pshistogram v3206.t -JXh -W250 -F -LP0.5p -V > plot.ps
If you know the distribution of your data, you may explicitly specify range and scales. E.g., to plot a histogram of the y-values (2nd column) in the file errors.xy using a 1 meter bin width, plot from -10 to +10 meters @ 0.75 cm/m, annotate every 2 m and 100 counts, and use black bars, run:
gmt pshistogram errors.xy -W1 -R-10/10/0/0 -Jxc/0.01c \ -Bx2+lError -By100+lCounts -Gblack -i1 -V > plot.ps
Since no y-range was specified, pshistogram will calculate ymax in even increments of 100.
Bugs¶
The -W option does not yet work properly with time series data (e.g., -f0T). Thus, such variable intervals as months and years are not calculated. Instead, specify your interval in the same units as the current setting of TIME_UNIT.