# Maple plot3d variable increment

I have an equation with two variables x and y.

I wish to plot a function in 3d (let's say cosine) with x and y as parameters.

I know the plot3d command in Maple is as follows:

Code:
plot3d(cos(x+y),x=-1..1, y =-1..1);
My question is this: how would I modify the increment values of x and y which are plotted?

For instance I want x=-1 to 1 but only in 0.25 increments and y=-1 to 1 in 0.1 increments.

A second question is: How do I display each value for what maple is plotting in 3d?
for instance:
f(x,y) = cos(x+y) => f(x,y) = ?
x = some value between -1 and 1 (in 0.25 increments)
y = some value between -1 and 1 (in 0.1 increments)

for question 2, basically i'm looking for something like [seq(f(x),x=a..b,increment)]

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LCKurtz
Homework Helper
Gold Member
I have an equation with two variables x and y.

I wish to plot a function in 3d (let's say cosine) with x and y as parameters.

I know the plot3d command in Maple is as follows:

Code:
plot3d(cos(x+y),x=-1..1, y =-1..1);
My question is this: how would I modify the increment values of x and y which are plotted?

For instance I want x=-1 to 1 but only in 0.25 increments and y=-1 to 1 in 0.1 increments.
I will answer your first question for the moment. You want to use the grid =[a,b] specification. That tells you how many grid points to plot. So if you want to go from -1 to 1 with 8 intervals of length .25, you need 9 grid points counting the start and end point. To go from -1 to 1 with 20 intervals of length .1 you need 21 grid points. So use:

plot3d(cos(x+y),x=-1..1, y =-1..1, grid = [9,21]);

LCKurtz
Homework Helper
Gold Member
A second question is: How do I display each value for what maple is plotting in 3d?
for instance:
f(x,y) = cos(x+y) => f(x,y) = ?
x = some value between -1 and 1 (in 0.25 increments)
y = some value between -1 and 1 (in 0.1 increments)

for question 2, basically i'm looking for something like [seq(f(x),x=a..b,increment)]
For your second question try this:
Code:
restart;
f := (x, y) → cos(x+y);
for k from 0 to 20
do
seq(f(-1+.25*j, -1+.1*k), j = 0 .. 7)
end;
I have used your 20 and 8 intervals as an example.

Awesome, this is exactly what I was looking for. I figured the first one I would need to specify a plot option but missed 'grid'.