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# Alexander

### MathWorks

37 total contributions since 2012

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I can use functions- "sym()" and "syms()".
The functions |sym| and |syms| are part of the Symbolic Math Toolbox. Are you sure that you have the Symbolic Math Toolbox insta...

alrededor de 7 años ago | 0

Removing exponents from a sysm class term
You can use |evalin| to do a substitution of the powers inside MuPAD: >> evalin(symengine, ['subs(', char(answer) ,', hold(_...

más de 7 años ago | 0

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Calculating Fourier Series Coefficients Using Custom Matlab Function
You forgot the index for assigning to |ak|. Also do you want the indefinite integral or an integral from 0 to 2*pi/w0? I added t...

más de 7 años ago | 0

Using latex command with anonymous functions
In R2012a I can do this: >> syms x y B(x) >> latex(B(x)) ans = B\!\left(x\right) >> latex(B(y)) ans = ...

más de 7 años ago | 1

Solved

Select every other element of a vector
Write a function which returns every other element of the vector passed in. That is, it returns the all odd-numbered elements, s...

más de 7 años ago

Solved

Given a and b, return the sum a+b in c.

más de 7 años ago

Solved

Determine if input is odd
Given the input n, return true if n is odd or false if n is even.

más de 7 años ago

Solved

Find the sum of all the numbers of the input vector
Find the sum of all the numbers of the input vector x. Examples: Input x = [1 2 3 5] Output y is 11 Input x ...

más de 7 años ago

Solved

Make the vector [1 2 3 4 5 6 7 8 9 10]
In MATLAB, you create a vector by enclosing the elements in square brackets like so: x = [1 2 3 4] Commas are optional, s...

más de 7 años ago

Solved

Times 2 - START HERE
Try out this test problem first. Given the variable x as your input, multiply it by two and put the result in y. Examples:...

más de 7 años ago

Solving a symbolic complex determinant by putting real and imaginary parts equal to zero??
Why do you split into real and imaginary part and solve both? I would expect this to work: S=solve(my_det, a1, a2) If I t...

más de 7 años ago | 0

Solve: Working only sometimes
Some of your variable get 'Inf' in between. If you want to use variable precision arithmetic, make sure you use syms. I get a re...

más de 7 años ago | 0

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How can I find the coefficients of the symbolic variables in a linear equation?

más de 7 años ago | 0

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Isolate Coefficients of Multivariate Linear Polynomial
If you know that you have only linear terms and only |x|, |r|, and |y|, you could use |diff| to get the coefficients: syms x...

casi 8 años ago | 0

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How to symbolically differentiate a function with respect to a different function
It seems as if you cannot differentiate with respect to a symbolic function. Maybe it helps if you substitute phi_dot with a nor...

casi 8 años ago | 0

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solve command
Seems to be the same problem as here: <http://www.mathworks.de/matlabcentral/answers/40281-substitution-after-differentiation-ea...

casi 8 años ago | 0

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Matlab simplify boolean expression
You have copied a MuPAD command. Did you use it inside a MuPAD Notebook? If not, type this at the MATLAB command prompt: mup...

casi 8 años ago | 0

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integration
Why do you think that the answer is incorrect? If you just want a number, use |double| on the result: >> double(H0) ...

casi 8 años ago | 3

Problem using subs in syms with matrix
The error raises in these lines: d=c(1); e=c(2); f=c(3); The variable |c| is a (1x1) sym and MATLAB cannot access the...

casi 8 años ago | 0

Substitute 3 variables in this symbolic equation
Maybe in this case the suggestion from Walter scales better: [X, Y, Z] = ndgrid(5:5:30, 1100:100:1500, 1:0.5:3); WnetF = m...

casi 8 años ago | 0

Matlab solve the integration in version 2008 but doesn't solve it in version 2011b
It seems that MuPAD gets confused by the assumptions. At the moment, |int| gives a huge result in piecewises. If you do the foll...

casi 8 años ago | 0

problem in this integration
Not sure what you want to do. Could it be, that you meant this: syms T T0 P b = 0.141;cp0 = 38.12;h0 = 1684;R= 8.314;Act_W...

casi 8 años ago | 0

solving nonlinear equations
I do get the following error message: Error using solve>processString (line 337) ' -0.0889=(-w^0.5*(w-1)^2*(w*(w+2)*sinh...

casi 8 años ago | 0

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eval() returns NaN when my matrix gets really big.
Please try the following: double(vpa(evalin(symengine, ['subs(' char(X) ', T=' num2str(T) ')']))) This does the followin...

casi 8 años ago | 0

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How to solve equation using math symbolic and get erfinv as output?
Hi Caio, If you have MATLAB R2012a you can simpliy use the <http://www.mathworks.com/help/toolbox/mupad/stdlib/assume.html as...

casi 8 años ago | 1

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Error while converting a HUGE symbolic equation to double (question edited and simplified further)
Does this work? subs(subs(Wnet, x, 5:5:30)', y, 1100:100:1500) respectively subs(subs(SFC, x, 5:5:30)', y, 1100:100...

casi 8 años ago | 0

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Golden Search Optimization Technique
I'm not familiar with the Golden Search algorithm, but it seems that you are overwritting |fx| by accident. If I remove those li...

casi 8 años ago | 1

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Wrong integration result with R2011b
Both answers are correct. Let me quote Wikipedia's entry for <http://en.wikipedia.org/wiki/Constant_of_integration Constant of i...

alrededor de 8 años ago | 0

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Integration In Matlab
Just use |double|: syms r R1=sqrt(3)*(2*r.^2-1) R2=sqrt(3)*(2*r.^2-1) b = .7; S=2*pi*imag(int(exp(1i*b*R1)*...

alrededor de 8 años ago | 0

| accepted