## a couple of newbie questions...

Asked by:

Hi all. I am using Maple 18.

1. How can I make maple NOT plot discontinuties with a vertical line? For example, plotting y=tan(x) displays vertical lines. Is there a setting to turn this off permanently?

2. When I type y=sin(x-Pi/2) and press enter, y = -cos(x) is displayed in blue. I am sure they are both the same thing, but I would like to see the expression that I typed, not an alternate expression that Maple wants to display.

3. Why do some expressions require a ; at the end, whilst others don't? Ie. y = sin(x) and y = 1+sin(x) do not, but y=2*sin(x) results in a "Warning, inserted missing semicolon at end of statement"

4. Is there a section on Mapleprimes(this site) where new users can ask questions? I would like to browse it to see what sort of problems other new Maples users have encountered. I am sure that my above questions may have been asked a few times over the years by newbies like myself.

Thanks in advance. :)

## Introduction to Thermodynamics

Maple 18

With this contribution we opened a breach in the proper use of the program applied Thermodynamics.

Introducción_a_la_Termodinámica.mw     (in spanish)

## Problem on the solution of Trigonometric Equations...

Asked by:

How can I know the solution is correct??

Here is the code:

s := solve(sin(x^2) = 1/2);
test := subs(x = s[1], sin(x^2) = 1/2);

## Avoid print quotes in maple output...

Asked by:

Hi all,

i have the following problem:

i had create this tiny procedure to compute the berstein base elements:

And so i would like print space, between B(i,n,t) and the formula corresponing, without quotes :D

In other word i would an output like this:

B(i,n,t),      ,(formula)

Thank you in advance :)

## Implicit Differentiation...

Asked by:

sin(xy) = x + y

subs( y(x)=y, solve( diff(subs( y=y(x), (1) ),x), diff(y(x),x) ) );

-1

subs( x(xy)=x, solve( diff(subs( x=x(xy), (1) ),xy), diff(x(xy),xy) ) );

cos(xy)

I can not get this answer to come out correctly when using this software please help. the correct answer in the back of the book is

1- y cos(xy)

--------------

x cos(xy) - 1

And is there a way that this program can tutor me on how to get this answer intead of spitting out the answer

the diff tutor only allows for a one sided equation to be entered.

## differentiation by "Diff"...

Asked by:

Hi. I want to differentiate the following expression using "Diff", not "diff". but I want to apply "Diff" to differentiate each separate term based on the chain rule. How can I do that? Does "Diff" apply chain rule for differentiation?

## Problem Loading MKL in Maple 18.01...

Asked by:

Hi Everyone,

I just upgraded a Linux 64-bit computer from Maple 17 to Maple 18.01.  Code that worked on Maple 17 no longer works on Maple 18.01.  The code uses BLAS matrix operations in in the LinearAlgebra package.  When the first such operation is called, I obtain the following fatal error:

MKL FATAL ERROR on loading the function mkl_blas_avx_xdcopy.

Maple 18.01 is unable to load any of the MKL routines even though the MKL shared libraries are in the Linux bin directory.  If I load my own MKL library (provided by Intel), Maple 18 will run these operatrions, but they ultimately lose precision which causes the program (which works fine in 17) to crash.  Any ideas about how to activate the version of MKL provided by Maple?  Will this version not loose floating-point precision?  Any help is greatly appreciated.

Best wishes.

David

University of Chicago

## Solution of quite complicated equation in terms of...

Asked by:

mode_shapes_and_critical_load(changed_model).mw

This is my code for finding mode shapes and critical load for a bimaterial strut under buckling.

Although everything else is working fine but I have a problem while solving for critical load.

h_new := convert(series(h, P, 3), polynom):

h_new := convert(series(h, P, 3), polynom):

without converting to polynomial, the code is unable to solve for P. Even on conversion, for differnet S values, I need to change the truncation order of conversion (like for S=0.5, it would work with 3 but for other S values I have to change truncation (convert(series(h, P, 6), polynom)), which also causes the number of solutions of equation to change which causes problem with plotting of graphs of critical load that I need (basically I need lowest two plots), thereby restricts me from automating the code with a for loop. I need to test it for various S values and then later in code I need to put teh critical load back and check mode shapes for different a values.

Is there a better way to solve two variable equation to get one variable in terms of another(the equation is quite complicated, contains trigonometric expressions).

and also if I try to automate the analysis for different S and a values, teh process needs to put teh value back in P which changes everything and teh next time loop operates it just ruins everything. Also there are varied number of solutions of P_crit for differnet S values which makes it difficult to store those solutions during automation?

## data table export...

Asked by:

hi,

I want to solve this to data table , i can plot but i need data in table

sol1 := dsolve([diff(u(theta),theta) = 427.2461*u(theta)+385620.123/u(theta)-25671.3871, u(0) = .6], numeric);

plots[odeplot](sol1, 0..0.18, color = red);

thanks.

## reliability result of DirectSearch...

Asked by:

how i can trust in DirectSearch solution result.is there any creteria?

my variable is intensity.

this is my code:

ep0 := 1/(4*3.14); el := 8.54*10^(-2); hbar := 1; vf := 1/300; kb := 1; tem := 2.586*10^(-2); ci := 1; p := 1.458*10^16; beta := 2; ai := 7.1*10^(-4); bi := ai/sqrt(3); enph := .196; d := enph/(kb*tem); n0 := 1/(exp(enph/(kb*tem))-1); gama := hbar*vf; intensity := 10000001; w := 1.55; impurity := 7.2*10^3;

g := hbar*beta/(bi^2*sqrt(2*p*enph)); aa := g^2*(n0+1)/(2*Pi*hbar*gama^2); bb := g^2*n0/(2*Pi*hbar*gama^2); cc := 2/(Pi*gama^2); l := (1*hbar)*w/(2*kb*tem);u := el^2*intensity/(32*w*hbar^2);

DirectSearch:-SolveEquations([op([((enph*ln(1+exp(c+enph/(kb*tem)))/(kb*tem)-polylog(2, -exp(c))+polylog(2, -exp(c+enph/(kb*tem))))*enph*(kb*tem)^2-(enph^2*ln(1+exp(c+enph/(kb*tem)))/(kb^2*tem^2)+2*enph*polylog(2, -exp(c+enph/(kb*tem)))/(kb*tem)+2*polylog(3, -exp(c))-2*polylog(3, -exp(c+enph/(kb*tem))))*(kb*tem)^3+(-exp(b)*enph*ln(1+exp(c+enph/(kb*tem)))+exp(c+d)*enph*ln(1+exp(b-d+enph/(kb*tem)))+exp(b)*kb*tem*polylog(2, -exp(c))-exp(c+d)*kb*tem*polylog(2, -exp(b-d))-exp(b)*kb*tem*polylog(2, -exp(c+enph/(kb*tem)))+exp(c+d)*kb*tem*polylog(2, -exp(b-d+enph/(kb*tem))))*enph*(kb*tem)^2/((exp(b)-exp(c+d))*kb*tem)+(exp(b)*enph^2*ln(1+exp(c+enph/(kb*tem)))-exp(c+d)*enph^2*ln(1+exp(b-d+enph/(kb*tem)))+2*exp(b)*enph*kb*tem*polylog(2, -exp(c+enph/(kb*tem)))-2*exp(c+d)*enph*kb*tem*polylog(2, -exp(b-d+enph/(kb*tem)))+2*exp(b)*kb^2*tem^2*polylog(3, -exp(c))-2*exp(c+d)*kb^2*tem^2*polylog(3, -exp(b-d))-2*exp(b)*kb^2*tem^2*polylog(3, -exp(c+enph/(kb*tem)))+2*exp(c+d)*kb^2*tem^2*polylog(3, -exp(b-d+enph/(kb*tem))))*(kb*tem)^3/((exp(b)-exp(c+d))*kb^2*tem^2))*bb+u*(1/(1+exp(-l-c))-1/((1+exp(-l-c))*(1+exp(l-b))))-(((1*enph)*(enph-2*kb*tem*ln(1+exp(-b+enph/(kb*tem))))/(2*kb^2*tem^2)+2*kb^2*tem^2*(-polylog(2, -exp(-b+enph/(kb*tem)))+polylog(2, -cosh(b)+sinh(b))))*enph*(kb*tem)^2-(enph^2*(enph-3*kb*tem*ln(1+exp(-b+enph/(kb*tem))))-6*kb^2*tem^2*(enph*polylog(2, -exp(-b+enph/(kb*tem)))+kb*tem*(-polylog(3, -exp(-b+enph/(kb*tem)))+polylog(3, -cosh(b)+sinh(b)))))*(kb*tem)^3/(3*kb^3*tem^3)-(-exp(b)*enph^2+exp(c+d)*enph^2-2*exp(c+d)*enph*kb*tem*ln(1+exp(-b+enph/(kb*tem)))+2*exp(b)*enph*kb*tem*ln(1+exp(-c-d+enph/(kb*tem)))+2*exp(c+d)*kb^2*tem^2*polylog(2, -exp(-b))-2*exp(b)*kb^2*tem^2*polylog(2, -exp(-c-d))-2*exp(c+d)*kb^2*tem^2*polylog(2, -exp(-b+enph/(kb*tem)))+2*exp(b)*kb^2*tem^2*polylog(2, -exp(-c-d+enph/(kb*tem))))*enph*(kb*tem)^2/((2*(-exp(b)+exp(c+d)))*kb^2*tem^2)-(exp(b)*enph^3-exp(c+d)*enph^3+3*exp(c+d)*enph^2*kb*tem*ln(1+exp(-b+enph/(kb*tem)))-3*exp(b)*enph^2*kb*tem*ln(1+exp(-c-d+enph/(kb*tem)))+6*exp(c+d)*enph*kb^2*tem^2*polylog(2, -exp(-b+enph/(kb*tem)))-6*exp(b)*enph*kb^2*tem^2*polylog(2, -exp(-c-d+enph/(kb*tem)))+6*exp(c+d)*kb^3*tem^3*polylog(3, -exp(-b))-6*exp(b)*kb^3*tem^3*polylog(3, -exp(-c-d))-6*exp(c+d)*kb^3*tem^3*polylog(3, -exp(-b+enph/(kb*tem)))+6*exp(b)*kb^3*tem^3*polylog(3, -exp(-c-d+enph/(kb*tem))))*(kb*tem)^3/((3*(-exp(b)+exp(c+d)))*kb^3*tem^3))*aa-u*(1/(1+exp(l-b))-1/((1+exp(-l-c))*(1+exp(l-b)))) = 0, -cc*polylog(2, -exp(b))+cc*polylog(2, -exp(-c))-impurity = 0])], tolerances = 10^(-8), evaluationlimit = 20000)

## Maple 18 Toolbox: Restart...

Asked by:

Hi Everybody,

I installed the Maple Toolbox for matlab and tried to run my old code.  For some reason, maple('restart') will cause Matlab to lock up.  Any ideas?

Windows 7 64-bit.  Matlab 2012b 32-bit, Maple 18 32-bit

## Compound Inequalities in Maple 18...

Asked by:

Here's an example compound inequality I'm working on.

Working it out manually....

Compound Inequality
4477.25 <= 4477.25+.25*(t-32450) <= 16042.25;

Distribute the coefficient
4477.25 <= 4477.25+.25*t - 8112.50 <= 16042.25;

Combine like terms
4477.25 <= -3635.25+.25*t <= 16042.25;

Add 3635.25 to all sides
8112.50 <= .25*t <= 19677.50;

Divide all sides by .25
32450 <= t <= 78710;

How can I ask Maple to simplify this compound inequality? Obviously this is not the correct syntax, It seems Maple doesn't understand what I want it to do.

4477.25 <= 4477.25 + .25 * (t-32450) <= 16042.25;

0.00 <= 0.25 t - 8112.50 and 0.25 t <= 19677.50                (112)

Also is there a way to ask Maple to only perform one step? In the above example, is it possible to ask Maple to "Distribute the .25", then show the result, next ask it to combine like terms, etc?

## Solving symbolic/numerical simultaneous equations?...

Asked by:

Hi,

I need to solve systems of numerical equations. I encountered a problem, where one of the parameters (tau[p3]) become FREE, see Maple worksheet attached.

That was clearly not expected.

I spent about 40 mintues to inspect what the problem is, eventually, I find that fsolve works perfectly.

Though fsolve would be the "first" choice for solving floating point problems. I really dont see why the simple "solve" syntax can not work. It is acting strange. And why is *tau[p3]*  FREE, not the others?

Could this be a bug? Or maybe is just WRONG to use solve?

Casper

solve-fsolve.mw

## trouble with basic linear equations...

Asked by:

I'm having some trouble maybe someone can point out my error please. I'm using the Maple 18 worksheet to try some basic linear equations. The trouble is in the last step.

1.) I start with 2 ordered pairs (2, 14) and (14,18)

Then I put in my formula to discover the slope. I confirm it looks correct in the Variables window.

m := (y2-y1)/(x2-x1);

2.)  Next I input the values for my ordered pairs. I also confirm thru the Variables window.

x1 := 2;

y1 := 14;

x2 := 3;

y2 := 18;

3.) Now I can type m and expect to get an answer to what my slope is.

m;

4.) Now I want Slope/Intercept form of y=mx+b. When I put in the formula y-y1=m(x-x1) i get a strange result

When I execute this formula, the result is y-14=4. (or thru context menu I tell it to solve for y, then I get y=18)

y-y1=m(x-x1)

When I manually input the values, the output is y-14=4x-8 (or thru context menu I tell it to solve for y, then I get y=4x+6)

y-14 = 4*(x-2)

Why is my equation (y-y1=m(x-x1)) not executing properly?

## PlotExpression in mini course not working?...

Asked by:

This is one is for Edgardo: In the "mini course", there is a command "PlotExpression" used that does not seem to do anything, at least for me. This is in a fresh Maple 18.01 installation on Linux with the latest version of Physics pulled off the Web today.

I cannot find any reference to PlotExpression in the Maple Help files, so where is this thing supposed to be defined? I >am< running a .mapleinit file of my own, configuring some of the plots[setoptions] parameters to my liking, but it should not clobber anything from the system mapleinit.

Another person managed to get the definition of PlotExpression and send it to me. From that I can see that the underlying plots:-plotcompare command seems to work, at least in part.

???

USPAS

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