Let's take another look at the dice rolling example:

Simulate rolling 8 dice 10 times.

roll := rand(1..6);
for i from 1 to 10 do;
dice := ['roll()' $8]; # dice contains 8 random values, each from 1..6
end do;

Let's say you want to check the list "dice" to see if all faces are
represented.

One way to do this is to write a proc which creates an array indexed
1..6; and initialize the array to zero; and then check the dice list ...
incrementing the associated array index for each value in the dice list.
Finally ... check the built array to see if all index values are non-zero.

A note added: Although the coding below is correct, it has clearly been superseeded by the following two entries contributed by acer: Entry 1 and Entry 2. As in any fairytale (even though this blog of mine certainly is not) it takes three of something (at least according to the fairytales of my fellow-countryman H. C. Andersen). Todays entry is the third and last (at least for now) in a row of three consecutive ones dealing with manipulations of indices of Arrays. The other two entries are Tip: Index an Array and Tip: Permute the indices of an Array.

In Maple 11, we added the ability to put captions on a plot. To do this, just use the 'caption' option with any plotting command, in the same way you'd use the 'title' option. These options are described in the plot/options help page. One additional change we made in Maple 11 for these two options is to allow the right-hand-side of the option equation to be a list containing the title or caption, followed by a 'font' suboption. So now you can use title=["my title", font=[times, bold, 20]] instead of having to specify the font separately with the 'titlefont' option. You can also display 2-D math in captions, titles and other text elements in a 2-D plot. To do this, simply use the mathematical expression as the option value: e.g. caption=x^2/2. To combine math with plain text, wrap everything in a 'typeset' structure: caption=typeset("my plot of ", x^2/2). If you enter the plotting command in 2-D math, you can use the palettes to build the expression directly in the command.

A note added: Although the coding below is correct, it has clearly been superseeded by the following two entries contributed by acer: Entry 1 and Entry 2 in the blog entry Tip: Transpose a pair of indices of an Array. Yesterday I wrote about a method to index an Array, using a procedure of the type `index/method`. Below, using the same sort of procedure, a method for permuting the indices of an Array is given (please feel free to suggest improvements; probably, the else-statement may be written more concisely):

Sometimes it can be very useful to know the indices of entries (of an Array) which obey some conditions. The following procedure (which works for any Array) makes this possible:

`index/makeIndex` := proc(indices::list,array::Array,value::list)
	# Retrieving from the Array
	if nargs = 2 then return array[op(indices)]: end if:
	# Storing in the Array
	if nargs = 3 then array[op(indices)] := indices = op(value): end if:
end proc:

An example: For Array A find the set S of indices of entries being positive integers, using as an intermediate step the Array B with entries of the form "indices = value":

I am just getting started with Maple TA for Calc III. I am trying to solve LaGrange multipliers. When the solve command returns multiple sets of answers, how do I extract the specific values for the subs command? $f=xyz; $q=x^2+2y^2+3z^2-6; $g=maple("f+mu*$q"); $exp1=maple("diff($g,x)"); $exp2=maple("diff($g,y)"); $exp3=maple("solve({$q,$exp1,$exp2},[x,y,mu])"); $ans1=maple("subs({x = ????,),y =???? )},$f)"); $ans2=maple("subs({x = ????,y = ????},$f)"); The question marks are where I am lost.

I'm finally going to start my MaplePrimes blog, and I will post answers to some of the questions I get about the areas with which I'm familiar. Most of time, I get asked about 2-D plotting. Some of the information here may be repeated from forum comments, but hopefully, this will make it easier to find. Unfortunately, my participation on MaplePrimes comes in spurts, as I try to find time between my other tasks, such as developing features for new releases. I tend to rely on the many Maple experts on MaplePrimes who very competently answer most questions that arise. I will, however, try to be diligent about adding a new tip at least once a week. Let's see if I can live up to my promise and get beyond this first post!

Hi, I am fitting experimental data DATA(t) to a MODEL(t) with LSSolve. What would be the shortest way to plot the residuals(t)? Thanks, Evgeni

I've downloaded and installed the new Vista ready version of Maple 11 (11.01) and few things are curious. It installs something called the "Maple 11 Reader Beta". Not sure what this is or what it is intended to do, but if it is a Maple runtime, then that is very interesting. We only have one Vista machine here in my office and the reader doesn't actually run on it so I can't really tell what it does. Which leads to a warning, the reader is failing because of a problem with my previous install of Maple 10. I had installed Maple 10 using the "run in XP compatibility mode" workaround. So before I went to install the new version I tried to uninstall Maple 10. But, I forgot to set the Maple 10 uninstaller to run in compatibility mode before I ran it, and it blew up. So the uninstall of Maple 10 failed part way through.

Please replace this text with the link to your file. The link can be found in the File Manager Hi, I'm having the nastiest time trying to get a plot from with DEplot3d. I suppose it's not really necessary to look at the whole maple file, but just this part: DEplot3d({de, w(t)= diff(z(t),t),D(x)(t)=diff(x(t),t), D(y)(t)=diff(y(t),t)},{x(t),y(t),z(t),w(t)}, t=0..2*Pi,[[w(0)=P,z(0)=0]], scene = [x(t),y(t),z(t)]) I'm trying to plot the solution to a second order diffeq, where x(t), and y(t) are known. Any help would be appreciated...I've been racking my brain for hours on this stuff

For double-precision ("hardware") real and complex floating-point operations on Matrices, Vectors, and Arrays Maple makes use of its external-calling mechanism to get to compiled code. A great deal of such compiled code for array operations requires what are known as Basic Linear Algebra Subprograms (BLAS). The BLAS libraries provide support not only directly for Matrix-Vector arithmetic but also indirectly in other external compiled libraries used by Statistics, ArrayTools, LinearAlgebra[Modular], etc.

Not sure if this is known or not, I couldn't find any reference to it. If you have a Maplet that you serve over the Internet using MapleNet, if the Maplet code has a trailing comment character - # -, then the Maplet won't display. You get the unhelp error message: "Exception is server did not return a correct Maplet Definition. Results were" It's a trivial problem once you find it, but finding it was not trivial. For the MapleNet developers. Take any Maplet, add a new line at the end of the file, put a comment character at the start of the line. The Maplet will not work. You can add the comment char to the .maplet file or to a .mw that is then exported. Happens in MapleNet 10.5 and MapleNet 11.

Just a thought for my day...

In a system which, by default, evaluates the arguments of function calls it is little strange to make a habit of using an unevaluated function call as a data structure.

Passing around such an object may result in unwanted evaluation of the stored data.

Can someone please explaint to me why this isn't working and some possible corrections. Any help would be greatly appreciated! I'm trying to solve 2 equation and 2 unknowns. Below is the code that I have... View 4496_instri.mw on MapleNet or Download 4496_instri.mw
View file details

I find that reading lots of help pages causes eye strain. A way of reducing this that works for me is to change the background color of the help pages from white to yellow. This can be done by setting HelpBGColor=255,255,224 in the ini file. On Windows XP the ini file will be found at C:\Documents and Settings\Joe User\maple9.ini or maple10.ini. For Maple 11, the file can be found at C:\Documents and Settings\Joe User\Local Settings\Application Data\Maple\11\maple.ini