Dear Maple users

As a followup on my recent question about how to count the number of characters in a string containing special Danish characters here: https://www.mapleprimes.com/questions/236478-How-To-Count-Length-Of-String-When-Special

I also need to handle substrings from a string in my work in Cryptography. In my attached file I present an example with a string containing two special characters. The problem is however, that I need to access individual characters in the string. Normally I would do so by using the command substring. As indicated in the file it doesn't work very well, because the special characters are represented by TWO elements (bytes)!

Is there a smart way to create a new command named SUBSTRING to accompanying the great LEN command suggested by vv?

Regards,

Erik V.

substrings.mw

Dear Maple users

I wanted to count the number of characters in a string containing special Danish letters beyond a...z. When using the special Danish letters æ, ø and å, those letters or characters are being counted as 2 characters each. I hope someone can help me having Maple count the length of strings containing those characters properly. 

Regards,

Erik V.

Dear Maple users

I have encountered a very strange error at one of my students. When using functions from the Expression Palette, she receives an error. It happens every time she is using this Palette. A reinstallation of Maple didn't help solve this issue. When using Command Completion for the very same function (for example cosine or square root), it works properly. 

She did send a Maple file to me in order for me to investigate it. I opened it and reexecuted the entire document. The error messages remained. I tried applying the functions from the Expression Palette myself resulting in the same errors. I even opened a new document and tried it again. Still an error. Then I closed Maple completely and opened it again. Within a new document, I applied a function from the Expression Palette. Now it worked!! I can't seem to understand  the logic behind this behavior. The file sent to me by the student obviously contain some kind of error, but why will this error spread to a new document, which I have opned on my own computer? My own computer does not have any issues with Maple. 

I have attached the Maple file with the errors and a screen shot. I hope someone can explain this strange behavior and tell me how I can help this student make Maple work again. 

Kind regards,

Erik V.

Maple file:

Error.mw

Dear Maple users

How do I turn a text into a Matrix of letters in the most convenient and effective way in Maple? Let's say the text contains N letters and the first n of these should be placed in the first row, the next n letters in the second row and so on. In my first question the text is one continous string of only letters a-z with no spaces or numbers, etc. 

My second question would be how I can do the same as above, if the text contains spaces, numbers and other special symbols, which should be ignored. 

The subject is Cryptography. I hope some can help.

Erik

Dear Maple users

I have created a simple Explore command in order to display what happens with a Planck curve when the temperature T increases - using the slider. Especially I would like to show how the maximum of the curve lies in relation to the visible spectrum from 400-700 nm, that is from 4*10^-7 to 7*10^-7. My idea was to somehow have this wavelength interval representing the visible spectrum displayed behind the Planck curve as a vertical rectangle. If it was a fixed plot, I could do it using the display command, but is it possible to add an extra plot to an Explore command?

I have uploaded the temporary Maple file and an image to show my intention (I don't expect the coloring ...)

Planck_curve.mw

Maybe someone can help?

Kind regards,

Erik V.