## 182 Reputation

17 years, 258 days

## surface integration...

Maple

Dear all:

I wonder how to integrate a function

f=t1^a1*t2^a2*t3^a3/(1-t1)^b1/(1-t2)^b2/(1-t3)^b3

over the surface

0<= t1,t2,t3 <=1, t1+t2+t3=1  ?

Thanks,

Peter

## plot3d on a nonsqure region...

Maple

Dear all:

I want to plot a function(say, z=x^2+y^2) on a nonsqure region(say, x^2+y^2<=1). What I did is to manually define a procedure so that it returns the function value if the sample point is inside the defined regioin, null otherwise.

region:=proc(x,y)
if x^2 + y^2 <= 1 then
return x^2+y^2;
else
return null;
end if:

end proc;

## color areas between two curves...

Maple

I hope to plot two functions f1:=x^2 ,f2:=x; and color regions in the 2d plane where f1(x) <  f2(x).  The function plot is easy but I don't know how to plot and color regions in 2D. The only solution I can think of is to sample points and use PLOT(POLYGONS())......

Is there any other ( easier !! ) ways to do this?

Thanks

## plot nonconvex polygons...

Maple

Dear all:

Maple help page says that POLYGONS() can only be used to plot convex polygons. I wonder how can I plot nonconvex polygons?

I tried a easy example
PLOT(POLYGONS([[0,0],[0,1],[1,1],[0.2,0.4],[1,0]]),COLOR(RGB,1,0,0));

which gives me sth. very strange plot...... :(