Assume that we have a vector-function:

I was digging through my old worksheets and came across something I created for one of my projects I never finished or well am still intending to work on.  Anyways I had come across a plot created in Matlab and noticed Maple didn't have an option to create gridlines in the axis on a 3d plot like Matlab did (at least I think it was Matlab) in any case I tried to mimic the same thing in Maple as exactly as I could.  The below is the groundwork I came up with and I...

Hello there, 

I have been having trouble removing elements from a list using the subsop tool.

I have a list A containing smaller lists of 2 values (A=[[0,1],[2,2],[4,5],[-1,-2], ... ]). My goal is to set boudaries to these sublists such as if the "y" (second value in any sublist) value is greater than 3, remove it from the list. here is what my code looks like

for i from i to n do
  if evalf(op(2,op(i,A))) < 0 then 
    subsop(i=NULL,A);
  fi;
od;

How to debug external DLL? IDE - MS Visual C++ Express 2010

After calling define_external from maple library succefully loaded. But how to unload it without closing maple? For example want change library file to new one.

I put Celsius in my equation and I get the wrong answer even though I've loaded the Units Package:

Download 25-25not_work.mw

I have to put in the conversion to Kelvin by myself to get the right answer:

Download 25-25_works.mw 

What am I doing wrong?

Thanks ahead of time!

Edo

Dear guys!

I'm solving an equation and then by its results I solve an integral, but I'm doing that for many initial conditions in a for loop. The problem is that when I change the limits of loop (or initial conditions) the result of integral in two for loop for a same initial condition are very different. What's the problem?

Thanks!

I was recently looking at rotating a 3D plot, using plottools:-rotate, and noticed something inefficient.

In the past few releases of Maple, efficient float[8] datatype rtables (Arrays or hfarrays) can be used inside the plot data structure. This can save time and memory, both in terms of the users' creation and manipulation of them as well as in terms of the GUI's ability to use them for graphic rendering.

What I noticed is that, if one starts with a 3D plot data structure containing a float[8] Array in the MESH portion, then following application of plottools:-rotate a much less efficient list-of-lists is produced in the resulting structure.

Likewise, an effiecient float[8] Array or hfarray in the GRID portion of a 3D plot structure gets transformed by plottools:-rotate into an inefficient list-of-lists object in the MESH portion of the result. For example,

restart:

p:=plot3d(sin(x),x=-6..6,y=-6..6,numpoints=5000,style=patchnogrid,
          axes=box,labels=[x,y,z],view=[-6..6,-6..6,-6..6]):

seq(whattype(op(3,zz)), zz in indets(p,specfunc(anything,GRID)));
                            hfarray

pnew:=plottools:-rotate(p,Pi/3,0,0):

seq(whattype(op(1,zz)), zz in indets(pnew,specfunc(anything,MESH)));
                              list

The efficiency concern is not just a matter of the occupying space in memory. It also relates to the optimal attainable methods for subsequent manipulation of the data.

It may be nice and convenient for plottools to get as much mileage as it can out of plottools:-transform, internally. But it's suboptimal. And plotting is a topic where dedicated, optimized helper routines for some particular data format is justified and of merit. If we want plot manipulation to be fast, then both Library-side as well as GUI-side operations need more case-by-case-optimizated.

Here's an illustrative worksheet, using and comparing memory performance with a (new, alternative) procedure that does inplace rotation of a 3D MESH. plot3drotate.mw

Hey guys,

I have the function f(x) =(sin(x) + 1)/(x^2 + 1) where x =-Pi/2 and 3Pi/2

1) I first set up an intgral for the function:

How can we get a color scheme that is stationary while object is rotated?

I'd like to shade an object in 3d but as I rotate it have the color scheme remain adjusted to a secondary set of axis.  Almost like a plot within a plot, rotate the inner plot with a color scheme relative to the outer plot axes.  An observer based color scheme I suppose is what I'm asking.

I suppose it would be similar to the way lighting schemes work, light from a specific...

Hello,

I would really appreciate some help. I am trying to use maple as a document of engineering analysis and calculations (like I would do in MathCAD), can maple handle such things. I seem to be having problems with the formatting. For example my units and outputs seem inconsistent, where am I going wrong. I have uploaded a file belwo for some advice please.

Also when I define a variable and then change the variables value can I get all the equations which...

Dear guys! Please look at the two following ways to solve a same equation and tell me why the results are different:

The initial conditions and the equation for both ways are:         m := 0.22: k := 0.03: n := 0.35: h := 0.63:

> eq := z-> 1=(m*(1+z)^3-k*(1+z)^2)*h^2/(H^2)+(((2*n-1)-(k*(1+z)^2*h^2/H^2))*((1-m+k)/(2*n-1+k))*((((H^2/h^2)-k*(1+z)^2)/(1-k))^(n-1))):

The first model:

> yp := implicitdiff(eq(z), H, z):

So, I do the following calculation and all is well

Units_Package_righ.pdf 

I close Maple, it asks me to save and I do.  Then I open the worksheet again and push the "!!!" button and I get

Units_Package_wron.pdf  

The calculation is done without the benefit of the units package.

Hi:

I have three lists: [x],[y1] and [y2] and want to plot y1 and y2 against x.

The command

pointplot(x,y1) gives me what I want for y1 and

pointplot(x,y2) gives me what I want for y2, BUT

I can't figure out a way to put y1 and y2 on the SAME plot against x instead of two separate plots.

There must be a way... any suggestions?

Thanks.

This might be a stupid question, but I'm a novice.

I'm using Minimize from the Optimization package, and the ansewr I get is x=5 (lets say).

now, I want to plot that 5 with it's y (let's say y=2), so what I really need is just the 5. not the x=5.

I can't seem to find how do I do that. convert has nothing, nor does anything else. I was thinking even to try and replace the = with := but I can't find how to.

anyone?? am I that stupid?