plot2d - 2D plot

Calling Sequence

plot2d([x],y)

plot2d([x],y,<opt_args>) (new syntax)

plot2d([logflag],x,y,[style,strf,leg,rect,nax]) (old syntax)

Parameters

• x,y : two matrices (or column vectors).
  • in the usual way x is a matrix of the same size than y (the column j of y is plotted with respect to column j of x)
  • if all the columns of x are equal (ie the abscissae of all the curves are the same), x may be simply the (column) vector of these abscissae (x is then a column vector of length equal to the row dimension of y).
  • when x is not given, it is supposed to be the column vector [1; 2; ...; row dimension of y].
• <opt_args> : This represents a sequence of statements key1=value1, key2=value2,... where key1, key2,... can be one of the following:
• style : sets the style for each curve, see below for value.
• leg : sets the curves captions. If this key is given and strf is not given then x character of strf is supposed to be 1. See below for value.
• rect : sets the bounds of the plot. If this key is given and neither frameflag nor strf is given then the y character of strf is supposed to be 7. See below for value.
• nax : sets the grids definition. If this key is given and neither axesflag nor strf is given then the z character of strf is supposed to be 1. See below for value.
• logflag : sets the scale (linear or logarithmic) along the axes. See below for value.
• frameflag : specifies how the frame of the plot is computed. The value is an integer ranging from 0 to 8. It corresponds to the y character of strf. See below.
• axesflag : specifies what kind of axes are drawn around the plot. The value is an integer ranging from 0 to 5. It corresponds to the z character of strf. See below.
• style : is a real row vector of size nc. The style to use for curve i is defined by style(i). The default style is 1:nc (1 for the first curve, 2 for the second, etc.).
• - if style(i) is negative or zero, the curve is plotted using the mark with id abs(style(i)); use xset() to set the mark id and xget('mark') to get the current mark id.
• - if style(i) is strictly positive, a plain line with color id style(i) or a dashed line with dash id style(i) is used; use xset() to see the color ids.
• - When only one curve is drawn, style can be the row vector of size 2 [sty,pos] where sty is used to specify the style and pos is an integer ranging from 1 to 6 which specifies a position to use for the caption. This can be useful when a user wants to draw multiple curves on a plot by calling the function plot2d several times and wants to give a caption for each curve.
• strf : is a string of length 3 "xyz" (by default strf= "081")
• x : controls the display of captions.
• x=0 : no caption.
• x=1 : captions are displayed. They are given by the optional argument leg.
• y : controls the computation of the actual coordinate ranges from the minimal requested values. Actual ranges can be larger than minimal requirements.
• y=0 : no computation, the plot use the previus (or default) scale
• y=1 : from the rect arg
• y=2 : from the min/max of the x, y datas
• y=3 : built for an isometric scale from the rect arg
• y=4 : built for an isometric plot from the min/max of the x, y datas
• y=5 : enlarged for pretty axes from the rect arg
• y=6 : enlarged for pretty axes from the min/max of the x, y datas
• y=7 : like y=1 but the previus plot(s) are redrawn to use the new scale
• y=8 : like y=2 but the previus plot(s) are redrawn to use the new scale
• z : controls the display of information on the frame around the plot. If axes are requested, the number of tics can be specified by the nax optional argument.
• z=0 : nothing is drawn around the plot.
• z=1 : axes are drawn, the y=axis is displayed on the left.
• z=2 : the plot is surrounded by a box without tics.
• z=3 : axes are drawn, the y=axis is displayed on the right.
• z=4 : axes are drawn centred in the middle of the frame box.
• z=5 : axes are drawn so as to cross at point (0,0). If point (0,0) does not lie inside the frame, axes will not appear on the graph.
• leg : a string. It is used when the first character x of argument strf is 1. leg has the form "leg1@leg2@...." where leg1, leg2, etc. are respectively the captions of the first curve, of the second curve, etc. The default is " ".
• rect : This argument is used when the second character y of argument strf is 1, 3 or 5. It is a row vector of size 4 and gives the dimension of the frame: rect=[xmin,ymin,xmax,ymax].
• nax : This argument is used when the third character z of argument strf is 1. It is a row vector with four entries [nx,Nx,ny,Ny] where nx (ny) is the number of subgraduations on the x (y) axis and Nx (Ny) is the number of graduations on the x (y) axis.
• logflag : a string formed by to characters h (for horizontal axis) and v (for vertical axis) each of these characters can take the values "n" or "l". "l" stands for logarithmic graduation and "n" for normal graduation. For example "ll"stands for a log-log plot. Default value is "nn".

Description

plot2d plots a set of 2D curves. Piecewise linear plotting is used.

By default, successive plots are superposed. To clear the previous plot, use xbasc().

See the meaning of the parameters above for a complete description.

Enter the command plot2d() to see a demo.

Other high level plot2d function exist:

plot2d2 : same as plot2d but the curve is supposed to be piecewise constant.

plot2d3 : same as plot2d but the curve is plotted with vertical bars.

plot2d4 : same as plot2d but the curve is plotted with arrows.

Examples

//simple plot
x=[0:0.1:2*%pi]';
plot2d(sin(x))
xbasc()
plot2d(x,sin(x))
//multiple plot
xbasc()
plot2d(x,[sin(x) sin(2*x) sin(3*x)])
// multiple plot giving the dimensions of the frame
//   old syntax and new syntax
xbasc()
plot2d(x,[sin(x) sin(2*x) sin(3*x)],1:3,"011"," ",[0,0,6,0.5])
xbasc()
plot2d(x,[sin(x) sin(2*x) sin(3*x)],rect=[0,0,6,0.5])
//multiple plot with captions and given tics
//   old syntax and new syntax
xbasc()
plot2d(x,[sin(x) sin(2*x) sin(3*x)],..
  [1,2,3],"111","L1@L2@L3",[0,-2,2*%pi,2],[2,10,2,10])
xbasc()
plot2d(x,[sin(x) sin(2*x) sin(3*x)],..
  [1,2,3],leg="L1@L2@L3",nax=[2,10,2,10],rect=[0,-2,2*%pi,2])
// isoview
xbasc()
plot2d(x,sin(x),1,"041")
// scale 
xbasc()
plot2d(x,sin(x),1,"061") 
// auto scaling with previous plots 
xbasc()
plot2d(x,sin(x),1)
plot2d(x,2*sin(x),2)
plot2d(2*x,cos(x),3)
// axis on the right 
xbasc()
plot2d(x,sin(x),1,"183","sin(x)")
// centered axis
xbasc()
plot2d(x,sin(x),1,"184","sin(x)")
// axis centered at (0,0)
xbasc()
plot2d(x-4,sin(x),1,"185","sin(x)")
 

See Also

plot2d1  plot2d2  plot2d3  plot2d4  xbasc  xset  

Author

J.Ph.C.