`champ`

: vector field in*R*^{2}//try champ x=[-1:0.1:1];y=x;u=ones(x); fx=x.*.u';fy=u.*.y'; champ(x,y,fx,fy); xset("font",2,3); xtitle(['Vector field plot';'(with champ command)']); //with the color (and a large stacksize) x=[-1:0.004:1];y=x;u=ones(x); fx=x.*.u';fy=u.*.y'; champ1(x,y,fx,fy);

Figdirfigures/

`fchamp`

: for a vector field in*R*^{2}defined by a function. The same plot than`champ`for a vector field defined for example by a scilab program.`fplot2d`

: 2D plotting of a curve described by a function. This function plays the same role for`plot2d`than the previous for`champ`.`grayplot`

: 2D plot of a surface using gray levels; the surface being defined by the matrix of the values for a grid.`fgrayplot`

: the same than the previous for a surface defined by a function (scilab program).In fact these 2 functions can be replaced by a usual color plot with an appropriate colormap where the 3 RGB components are the same.

R=[1:256]/256;RGB=[R' R' R']; xset('colormap',RGB); deff('[z]=surf(x,y)','z=-((abs(x)-1)**2+(abs(y)-1)**2)'); fgrayplot(-1.8:0.02:1.8,-1.8:0.02:1.8,surf,"111",[-2,-2,2,2]); xset('font',2,3); xtitle(["Grayplot";"(with fgrayplot command)"]); //the same plot can be done with a ``unique'' given color R=[1:256]/256; G=0.1*ones(R); RGB=[R' G' G']; xset('colormap',RGB); fgrayplot(-1.8:0.02:1.8,-1.8:0.02:1.8,surf,"111",[-2,-2,2,2]);

Figdirfigures/

`errbar`

: creates a plot with error bars