C Library Functions - graph (3)
NAME
graph(3) - [M_graph] Draw an XY graph
CONTENTS
Synopsis
Description
Options
Example
Author
SYNOPSIS
subroutine graph(x,y,ndp,ndl,f,c,nc)
DESCRIPTION
This is an XY graph routine that is intended to be very self-contained and easily ported to various graphics libraries. This version is callable from the M_draw(3f) module.
It is being ported from the LONGLIB public domain library and will be changing. It is recommended that you rename the M_graph(3f) module source to freeze a copy at this point, as new versions will not necessarily be upward compatible. The underlying calls to M_graph(3f) should not require any changes.
graph(3f) is a general routine for plotting lines or scatterplots. Optionally, error bars and symbols can be added. graph(3f) differs in philosophy from other libDL MASTER routines in that plotting options are passed via an option array. The routine is designed to produce a reasonable plot with the option array set to all zeros. The output format is changed by initializing selected array elements to the values described below. This permits simple but flexible specification of the plot format.
OPTIONS
The optional error bar specification, when non-zero, changes interpretation of lines. The first line (and every third line) is considered a "center" line. The second line specifies the relative error (to be added to the first line) used for plotting the tops of the error bars. The third line is used similarly to locate the bottoms of the error bars. When the error bar specification is negative the center line points are marked with a special "x" (in addition to any other option). The absolution value of the specification determines the type of error bar according to the following table.
x (R): x input array dimensioned x(ndp,ndl). y (R): y input array dimensioned y(ndp,ndl). ndp (i): number of data points per line ndl (i): number of data lines f (R): option array dimensioned at least f(53) (described below)c (C): array of strings dimensioned C(3+ndl) c(1) : x axis title c(2) : y axis title c(3) : top title c(4) : line 1 legend (optionally used) c(5) : line 2 legend (optionally used) ... ...nc (i): array of string lengths dimensioned nc(3+ndl) nc(1) : number of characters to use in C(1) nc(2) : number of characters to use in C(2) ... ...The array elements of the option array f are interpreted according to the following table. Some parameters have default values (shown in square brackets). These are used when the input value is zero. A simple plot may be produced by setting all the elements of f to zero. Note that user specified input scaling factors should be powers of ten when the log axis specification is selected. An optional legend may be plotted. The legend consists of a column of lines and the labels from n(4:)
array range of index values action for each value------- -------- ------------------------
1 0<=.<=ndp number of points/line to plot [ndp]: 0=ndp used 2 0<=.<=ndl number of lines to plot [nl]: 0=ndl used 3 -1/0/1 x scale: 0=auto,smoothed; 1=auto,nosmooth; -1=user 4 xmin user supplied scale value (used if f(3)<0) 5 xmax user supplied scale value (used if f(3)<0) 6 -1/0/1 y scale: 0=auto,smoothed; 1=auto,nosmooth; -1=user 7 ymin user supplied scale value (used if f(6)<0) 8 ymax user supplied scale value (used if f(6)<0) 9 0/1 x value usage: 0=first line of x data array used for all y lines; 1=lines of x,y paired 10 0/1 connect plotted points: 0=yes; 1=no 11 >=0 symbol plotted every ()th point: 0=no symbols 12 >=0 line symbol size [0.1]: 0=use default 13 >=0 symbol number for first data line, each line then uses next symbol in sequence 14 8<.<8 error bar option (see below): 0=no error bars 16 >=0 error bar size [0.1]: 0=default used 17 0/1 vertical line from points to reference value: 0=no; 1=yes 18 rval reference value 19 -1/0/1 x axis type: 0=linear; 1=log axis, -1=no axis 20 -1/0/1 y axis type: 0=linear; 1=log axis, -1=no axis 21 >=0 x axis length [7.0]: 0=default used 22 >=0 y axis length [5.0]: 0=default used 23 >=0 x axis tick pattern (see axisc_) [7.00]: 0=default 24 >=0 y axis tick pattern (see axisc_) [5.00]: 0=default 25 0/1 x axis title side of axis: 0=below; 1=above 26 0/1 y axis title side of axis: 0=left; 1=right 27 0/1 x axis auto exponent enable: 0=enable; 1=disable 28 0/1 y axis auto exponent enable: 0=enable; 1=disable 29 0/1 x axis tick side: 0=below; 1=above 30 0/1 y axis tick side: 0=left; 1=right 31 0/1 x axis number orientation: 0=horizontal; 1=vertical 32 0/1 y axis number orientation: 0=vertical; 1=horizontal 33 0/1 x axis numbers/title: 0=shown; 1=not shown 34 0/1 y axis numbers/title: 0=shown; 1=not shown 35 0/1 use x=log10(abs(x values)+1.e-34): 0=no; 1=yes 36 0/1 use y=log10(abs(y values)+1.e-34): 0=no; 1=yes 37 -1/0/1 add mirror x axis: 0=no; 1=w/labels; -1:w/o labels 38 -1/0/1 add mirror y axis: 0=no; 1=w/labels; -1:w/o labels (mirrored axes placed on opposite from normal axis) 39 >=0 x axis label size [0.15]: 0=use default 40 >=0 y axis label size [0.15]: 0=use default 41 >=0 top title character size [0.18]: 0=use default 42 0/1/2/3 grid: 0=no grid; 1=solid; 2=dotted; 3=ticked 43 -1/0/1 legend: 0=no legend; 1=right side; -1=user locate 44 xval user specified lower-left corner of legend 45 yval user specified lower-left corner of legend 46 0/1 show plot symbol on legend: 0=no; 1=yes 47 0/1 show line segment on legend: 0=no; 1=yes 48 >=0 legend character height [0.12]: 0=use default 49 >=0 legend line segment length [0.5]: 0=use default 50 -1/0/1 top title justify: 0=center; -1:left; 1:right 51 0/1 plot horizontal reference line: 0=no; 1=yes 52 0/1 use linetype array values: 0=no; 1=yes 53 0/1 use color array values: 0=no; 1=yes 54 >=0 color index #1: 0=color value 1 used 55 >=0 linetype index #1 56 >=0 color index #2: 0=color value 1 used 57 >=0 linetype index #2 ... [char46].. ... etc ...
value type of error bar ------ --------------------------------------------------- 1 line connecting relative errors 2 1 + horizontal bars at relative errs 3 1 + vertical bars at relative errs 4 double line connecting rel. errs+horizontal bars 5 double line connecting rel. errs+vertical bars 6 vertical rectangle w/top and bottom rel. errs 7 rectangle with corners at relative errorsThe color and line type index (when enabled) are used according to the following table.
index # color usage linetype usage --------- ------------- ---------------- 1 x axis x axis 2 x axis numbers y axis 3 x axis title title 4 x axis exponent legend titles 5 y axis reference line 6 y axis numbers error bars 7 y axis title line #1 linetype 8 y axis exponent line #2 linetype 9 title etc. 10 legend titles ... 11 reference line ... 12 grid ... 13 line #1 color ... 14 line #2 color ... ... ... etc. ... ...
EXAMPLE
Sample program that creates some simple curves and then prompts for index values and values in the options array to allow for testing various options.
program demo_graph use m_graph, only : graph, graph_init use M_drawinteger,parameter :: numlines=3 integer,parameter :: numpts=25 integer,parameter :: nf=255 real :: x(numpts),y(numpts,numlines) character(len=80) :: c(numlines+3) integer :: nc(numlines+3) real :: f(nf) character(len=20) :: device integer :: ixsize integer :: iysize character(len=:),allocatable :: filename integer :: w device=’x11’ ixsize=1200*.75*0.5 iysize=900*.75*0.5 w=40 if(device.eq.’x11’)then call prefposition(0,0) call prefsize(ixsize,iysize) else call prefsize(ixsize,iysize) !!call voutput(str(filename,’_’,int(a),’x’,int(b),’.’,device,sep=’’)) endif call vinit(device) call vsetflush(.false.) call vflush() call linewidth(w)
! fill some arrays with data we can plot DO i20=1,25 X(i20)=i20 Y(i20,1)=i20**2+5.0 Y(i20,2)=i20*20.0 Y(i20,3)=(-3.0)*(i20/4.0)**3 enddo
f=0.0 ! zero out option array ! set up color and linetype in option array do i70=55,nf,2 f(i70)=mod(i70,7) f(i70-1)=mod(i70,7) enddo f(52)=1 f(53)=1
ndp=numpts! number of data points per line ndl=3 ! number of data lines !c ! array of strings dimensioned c(3+numpts) c(1)=’X-AXIS’ ! c(1) : x axis title c(2)=’Y-AXIS’ ! c(2) : y axis title c(3)=’TITLE’ ! c(3) : top title c(4)=’LABEL 1’ ! c(n) : line N-3 legend (optionally used) c(5)=’LABEL 2’ ! c(n) : line N-3 legend (optionally used) c(6)=’LABEL 3’ ! c(n) : line N-3 legend (optionally used) !nc ! array of string lengths in c() dimensioned nc(3+numpts) do i60=1,6 nc(i60)=len_trim(c(i60)) enddo !f(39)= 0.25 !f(40)= 0.25 !f(42)= 3.00 !f(43)=-1.00 ! initialize graphics call graph_init(12.0,9.0, 1.00,1.00, 1.0) INFINITE: do CALL graph(X,Y,NDP,NDL,F,C,NC) call vflush() 888 continue write(*,*)’Enter index and value for graph(3f) option array:’ read(*,*,end=999,err=888)index,value if(index.lt.1)then exit INFINITE elseif(index.gt.nf)then goto 888 else f(index)=value write(*,*)’index ’,index,’ now ’,value endif call vflush() ! flush graphics buffers call color(7) call clear() call color(0) call vflush() ! flush graphics buffers enddo INFINITE 999 continue call vflush() ! flush graphics buffers call vexit() ! close up plot package stop end program demo_graph
AUTHOR
Based on [LONGLIB93.SOURCES.FORTRAN.MASTER]graph.FOR
| ! | WRITTEN: Version 1.0 SEPT. 1987 - DGL Version 2.0 20-JAN-1994 17:13:12.80 Version 3.0 Wed Jun 12 10:34:11 MDT 1996 |
| Nemo Release 3.1 | graph (3) | February 23, 2025 |
