As a geotechnical engineer, much of what I calculate relates to depth or settlement.  Which, by tradition, is signed as positive in the vertically down direction.  Hence, I want to be able to produce graphs with positive y-values (e.g. depth, settlement, etc.) plotted in the downward direction (effectively, all I want to do is simply reverse the direction of the y-axis).  One workaround is to simply multiply all y values by -1 before plotting.  But this isn't ideal (as the values show as negative).  I've had a look through the documentation and haven't found a clean way of doing this.  Is anyone able to confirm whether its possible?  Or am I wasting my time looking?  Thanks in anticipation, Ian

I can't cut and paste from my maple worksheet (because syntax somehow gets changed in the process), so perhaps the following attempt at carefully worded  prose will do (alternately, please someone tell me how to attach screen shots).  Here goes...

I execute

The optimization succeeds and the assignment takes place.  The result is what I'ld like to cut and paste so youall can see...  it looks as follows. 'r:=' (but no quotes)  followed by open square bracket, then a number, then a comma, then another open square bracket, then a vertically arranged list of stuff, then two close brackets.  I presume the vertically arranged stuff in the innermost matching square brackets somehow represents the point in the search space where the minimum takes place, and the minimum is the number that follows the first square bracket and is before the comma.  My goal is to write to disk the the point in the search space where the minimum takes place (I suppose that vector is in some sense r[2]) .  My attempt to write it to disk is

ExportMatrix("maple.txt", r[2], target = auto)

but maple complains

ExportMatrix("maple.txt", r, target = auto);
Error, invalid input: ExportMatrix expects its 2nd argument, M, to be of type {Matrix, list(Matrix)}, but received [293148935266.099426, Vector(28, {(1) = -233674.34818878854, (2) = 12.62636610207248, (3) = 0.3337043409389546e-2, (4) = 0.13303915611938133e-1, (5) = .0, (6) = .2589485687872699, (7) = 0.9341600279762804e-1, (8) = 0.3293862590239189e-1, (9) = 0.12892649003200331e-1, (10) = 0.606528143324688e-1, (11) = 0.17524827222051658e-1, (12) = -0.16059611469561555e-17, (13) = 0.621465506367271e-1, (14) = .29826235341855, (15) = -0.16288776533795546e-17, (16) = 0.15301368661023716e-1, (17) = 0.1529933711903137e-18, (18) = 0.4375115591744606...

How can I write the result of optimization to disk as a plain ascii text file (tsv format)?

Thanks

hope you can understand it.

I'm looking for the Maplets package for Maple 7 that was available on the old mapleprimes.  Does anyone have it?

I did not realize Maple 2016, since Maple 2015 actually, had stopped Windows XP support. 

hi

how i can remove this error?

1) ''Error, invalid input: lhs received diff(diff(diff(diff(w(x, y, t), x), x), x), x)+.12*(diff(diff(diff(diff(w(x, y, t), x), x), y), y))+0.11e-2*(diff(diff(diff(diff(w(x, y, t), y), y), y), y))+10-.4*(diff(diff(w(x, y, t), x), x))-0.4e-2*(diff(diff(w(x, y, t), y), y))+diff(diff(w(x, y, t), t), t)-w(x, y, t)-tau, which is not valid for its 1st argument, expr'''''

2)'' Error, incorrect number of extra arguments in select''

thanks

scale.mw
 

Download scale.mw

Hello,

Let matrix A be nxn matrix. How to find modal matrix M, the modal matrix for the matrix A is the n × n matrix formed with the eigenvectors of A as columns in M? (D=M^-1*A*M, where D is dioganal matrix with the eigenvalues of A on the main diagonal of D)

For example;

How to find M modal matrix?

Goodmorning,

Has the command DGinfo(T,"CoefficientSet") an equivalent in the Physics package ? is there another way to extract the non-zero elements from the Einstein tensor in a format acceptabele to pdsolve?

Many thanks,

Luc Van Gompel

Hi.

In some cases when dealing with vectofields an such the are integral has to be expressed in terms of r(t).

the general form for r is r^2=(r*cos(t)-a)^2+(r*sin(t)-b)^2, When I solve this in maple it seems like I get the inverse of the desired result.

If I knew that was always the case I could just inverse my result to get the right expression for r, but im not sure if it only applies for this particular cas or all cases.

I would be happy if anyone took a quick look and suggested a way to obtain the desired solution for any center (a,b) for the circle.

Download parametrization_of_r_not_centred_at_orgin.mw
 

I would also happily like to know how I can solve for the range r can take, obviously in the example i´m working with here r starts at 0, but that is not always the case i guess.

Thank you, your help is much apperciated

Hello

I changed the color of the background of a worksheet in black (I introduced a Table for that reason) because the white color hurts my eyes. I still have a couple of things that I'd like to modify:

1. The blinking cursor is black and is now invisible. How can I change its color?

2. The default input color is red ; i'd like to change it in white. How can I do?

Thanks Nicola

How do I genereate random negative numbers?

when i put a minus sign in the rand-function i get an error.

I need to for example generate a random number between -r and r, where r is the input

Is there a difference between scoping rules for regular procedures and for arrow operators?

      Inspired by the theme
http://www.mapleprimes.com/questions/219995-Finding-A-Convinient-Parametrization-Of-Surfaces
Examples in the Mathematica did Alexander Bannikov.
It is equidistant radius 0.1 to the surface

   (x1 ^ 2 + x2 ^ 2-0.4) ^ 2 + (x3 + sin (x1 * x2 + x3)) ^ 4-0.1 = 0;

https://vk.com/doc7819263_439405418?hash=af46d61d8aad95f70b&dl=9f245f5b6b68b47075

and an example of parameterization the same surface

https://vk.com/doc7819263_439432143?hash=36cf31d52c97e2e373&dl=7e4fa17a771dffb331

As I have understood from the words of Alexander Bannikov, parameterization was performed using the functions: RegionFunction, ContourPlot3D, ClippingPlanes.

It turns out that Maple functions inferior?

Hi everybody, 

I am working with Maple 2015.2 ; system = OS X El Capitan
I would like to compare the outputs of two files by using  the Worksheet:-Comparator command

OriginalFile.mw file contains this single instruction
> a:=1;

ModifiedFile.mw contains this single instruction
> a := 2;

Both us are located on my desktop, which is also my current directory in the worksheet from which I am going to run the comparison.

MyDir := cat(currentdir(), "/Desktop/");
OriginalFile := cat(MyDir, "OriginalFile.mw"):
ModifiedFile := cat(MyDir, "ModifiedFile.mw"):

# to verify that all is going well I use these two commands 
# Worksheet:-DisplayFile(OriginalFile):
# Worksheet:-DisplayFile(ModifiedFile):

Running the  command  Worksheet:-Comparator(OriginalFile, ModifiedFile) returns me error messages :
The first one is  (after having selected  "compare" and next "run" in the Comparator Maplet) 

and the second one (after having cliked ont the "OK" button" on this alert window)

Note that the same thing happens if I use Worksheet:-Comparator() and select the two files with the browsers
Could you please help me to understand what happens ?

Thanks in advance

How do I solve the problem that attached? Please give me the correction. thank you