This is a follow-up to an earlier post about CovarianceMatrix.

There are several ways in which Statistics:-CorrelationMatrix can be improved.

CorrelationMatrix shares some inefficiencies with CovarianceMatrix, by computing correlations between the n columns, pairwise. But in doing so it also computes...

This function

f(x) = { 0,           x = 0
          { 1 - x,      0 < x < = 1

is not continuous on [0, 1].

So I wrote

f := x -> piecewise (x = 0,0,x > 0,1-x);
plot(f,0..1);

But Maple doesn't show the lack of continuity. (discont=true doesn't do anything here). Can I improve the plot?
 

Alla

Why does Maple fail to respond to

solve( {(560/243)*(x+1)^(-13/3)},{x});

I'm an autodidact working with calculus and Maple 9.5,  I find the Maple Learning Guide more illustrative than comprehensive and the help files too oriented toward users who know more math and/or more Maple than I do.  This forum has proved helpful in responding to specific questions, but I'm looking for some books that would provide guidance on the full range of Maple's potential.  I'm not looking for a primer, but rather something as comprehensive as the help files that makes fewer assumptions about the reader's knowledge and is written

Would someone please give me the correct syntax for finding extrema on a closed interval for

f(x) = 3x^4 - 4x^3  on the interval [-1, 2]

that would include the left & right endpoints should one of those be the maximum or minimum.

Alla

How would you graph the eight curve in Maple?

x^4 = a^2 (x^2 - y^2)

Alla

In a previous post I described how to call OpenMaple from a C# application (see: Using OpenMaple with C#) Now, I'd like to tackle the reverse problem: how do I call a C# .dll from within Maple? The way to do this involves using Component Object Model (COM) interoperability in the Microsoft .NET Framework. Because Maple's kernel is written in an "unmanaged" language, a wrapper is needed in order to bridge to your managed C# code. This article will outline the steps needed to create this bridge and get Maple talking to C#.

Some years ago, before the advent of the Statistics package, a colleague asked for a fast way to generate thousands of normally distributed random numbers in Maple. The suggestion that worked quickest and most easily (using existing, simple Maple Library routines) was to generate random deviates using the usual formula associated with the distribution. But the key was to replace the scalar values (representing the uniformly distributed input) with a whole Matrix of input values....

I wanted to see how difficult it would be to use the OpenMaple API from a C# program.  It turns out that it is pretty easy to access C .dlls from C#.  I was able to reproduce a commandline equivalent (minus the command history and editing features). 

The source code can be found here: openmaple.cs

  restart; Digits:=14;     # using Maple 12.02
  J:=Int(arctan(z)^2/(1+4*z^2),z=0..infinity);


  evalf(J);
                           0.40325004753375

  value(J); evalf(%); Re(%);

                ...

Following the midi crash course written by Daniel White, and using a table of midi note numbers, it is rather easy to write a Maple procedure producing midi files. Here is an example that I posted in Simple Sounds thread, slightly modified by adding an instrument as a 3rd parameter:

An annoying feature of Maple is that if it crashes (all too often) & you have not given your worksheet a name, the file is lost despite having activated Auto-Save.

1)   Is the previous statement correct for Maple 9.5?

2)   If so, has this bug been corrected in later versions?

Alla

The Maplesoft office is currently in the process of being burried in snow and many of us are getting ready to head off for the holidays.  Before leaving, I wanted to share this great animated GIF created using 3d plots.  It was sent to me by Bruce Char at Drexel University. The greeting and the Maple script to generate it are after the break.

In my previous post, I was parsing data out of HTML tables so that I could glean some trivia from it.  My true goal was to compile data out of dozens of such tables and so I needed a way to do the whole process in Maple.   So, now, here is how I used Sockets and StringTools to automate the whole process.

Recently there was some discussion in the Maplesoft office about unisex baby names (that is, names that nearly as likely to belong to males as females). Whenever discussing names, I usually head to the US Social Security Administration's wonderful baby names site. They have data on the top 1000 male and female names for children born in the US each year for more than the last century (that includes about 80% of names). They slice the data a little by US state, and popular names for twins and such, but they do not include data on unisex names. So, I applied Maple to the task.