plot2d_old_version

Arguments

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].

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.

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 clf().

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

Enter the command plot2d() to see a demo.

Other high level plot2d function exists:

• 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 vertical arrows.

Examples

//simple plot 
x=[0:0.1:2*%pi]';
plot2d(sin(x))
clf()
plot2d(x,sin(x))
//multiple plot
clf()
plot2d(x,[sin(x) sin(2*x) sin(3*x)])
// multiple plot giving the dimensions of the frame 
// old syntax and new syntax
clf()
plot2d(x,[sin(x) sin(2*x) sin(3*x)],1:3,"011","",[0,0,6,0.5])
clf()
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
clf()
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]);
clf()
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
clf()
plot2d(x,sin(x),1,"041")
// scale
clf()
plot2d(x,sin(x),1,"061")
// auto scaling with previous plots
clf()
plot2d(x,sin(x),1)
plot2d(x,2*sin(x),2) 
plot2d(2*x,cos(x),3)
// axis on the right 
clf()
plot2d(x,sin(x),1,"183","sin(x)")
// centered axis 
clf()
plot2d(x,sin(x),1,"184","sin(x)")
// axis centered at (0,0)
clf()
plot2d(x-4,sin(x),1,"185","sin(x)")

See Also

• plot2d1 — 2D plot (logarithmic axes) (obsolete)
• plot2d2 — 2D plot (step function)
• plot2d3 — 2D plot (vertical bars)
• plot2d4 — 2D plot (arrows style)
• clf — clear or reset the current graphic figure (window) to default values
• xset — set values of the graphics context. This function is obsolete.

Authors

J.Ph.C.