How do I access and assign values given by the solve command

for example

f := unapply(x*(8*x^2+5*x+cos(y)), x, y);

p := solve({diff(f(x, y), x) = 0, diff(f(x, y), y) = 0}, {x, y})

This gives the following

{x = 0, y = (1/2)*Pi}, {x = -1/6, y = 0}, {x = -1/4, y = 0}, {x = -1/2, y = Pi}, {x = 1/12, y = Pi}

now if I type: p[1] I get the following

{x = 0, y = (1/2)*Pi}

Now this isn't very useful. I want to access the "0" and the "(1/2)*Pi". How do I do that?

I have been using random numbers in Maple and want to generate a sum of that random number. I have consider the following

with(stats):

x = random[uniform](10);

and now want 

sum(x_i)^a

where (x_i) is the ith values in x (random array) and "a" is any real number.

in maple 2017 I have enconterd a problem in showing of matrix elements. this error did not exist in maple 2016.

after some mathematical operations with(Linearalgebra)

I have obtained a matrix but maple shows it as below

`Vector(3, {(1) = \`+\`(\`*\`(0.19498673e10, \`*\`(\`^\`(x[1], 3))), \`-\`(\`*\`(0.36539123e10, \`*\`(\`^\`(x[1], 2), \`*\`(x[2])))), \`*\`(0.12514628e10, \`*\`(\`^\`(x[1], 2), \`*\`(x[3]))), \`-\`(\`*\`(7987.1506, \`*\`(\`^\`(x[1], 2)))), \`*\`(0.35170874e10, \`*\`(x[1], \`*\`(\`^\`(x[2], 2)))), \`-\`(\`*\`(0.41418339e10, \`*\`(x[1], \`*\`(x[2], \`*\`(x[3]))))), \`-\`(\`*\`(9187.8615, \`*\`(x[1], \`*\`(x[2])))), \`*\`(0.28788960e10, \`*\`(x[1], \`*\`(\`^\`(x[3], 2)))), \`*\`(2871.4325, \`*\`(x[1], \`*\`(x[3]))), \`-\`(\`*\`(0.95594712e9, \`*\`(\`^\`(x[2], 3)))), \`*\`(0.21616680e10, \`*\`(\`^\`(x[2], 2), \`*\`(x[3]))), \`-\`(\`*\`(16552.293, \`*\`(\`^\`(x[2], 2)))), \`-\`(\`*\`(0.20009067e10, \`*\`(x[2], \`*\`(\`^\`(x[3], 2))))), \`-\`(\`*\`(30447.582, \`*\`(x[2], \`*\`(x[3])))), \`*\`(0.42009564e9, \`*\`(\`^\`(x[3], 3))), \`-\`(\`*\`(42372.407, \`*\`(\`^\`(x[3], 2))))), (2) = \`+\`(\`-\`(\`*\`(0.14713991e11, \`*\`(\`^\`(x[1], 3)))), \`*\`(0.42489026e11, \`*\`(\`^\`(x[1], 2), \`*\`(x[2]))), \`-\`(\`*\`(0.25018214e11, \`*\`(\`^\`(x[1], 2), \`*\`(x[3])))), \`-\`(\`*\`(55498.093, \`*\`(\`^\`(x[1], 2)))), \`-\`(\`*\`(0.34645652e11, \`*\`(x[1], \`*\`(\`^\`(x[2], 2))))), \`*\`(0.52229109e11, \`*\`(x[1], \`*\`(x[2], \`*\`(x[3])))), \`-\`(\`*\`(399927.96, \`*\`(x[1], \`*\`(x[2])))), \`-\`(\`*\`(0.24172439e11, \`*\`(x[1], \`*\`(\`^\`(x[3], 2))))), \`-\`(\`*\`(367829.40, \`*\`(x[1], \`*\`(x[3])))), \`*\`(0.11603445e11, \`*\`(\`^\`(x[2], 3))), \`-\`(\`*\`(0.24618238e11, \`*\`(\`^\`(x[2], 2), \`*\`(x[3])))), \`*\`(163169.71, \`*\`(\`^\`(x[2], 2))), \`*\`(0.24814370e11, \`*\`(x[2], \`*\`(\`^\`(x[3], 2)))), \`-\`(\`*\`(711030.81, \`*\`(x[2], \`*\`(x[3])))), \`-\`(\`*\`(0.64758011e10, \`*\`(\`^\`(x[3], 3)))), \`*\`(427083.52, \`*\`(\`^\`(x[3], 2)))), (3) = \`+\`(\`*\`(0.13627334e11, \`*\`(\`^\`(x[1], 3))), \`-\`(\`*\`(0.67651416e11, \`*\`(\`^\`(x[1], 2), \`*\`(x[2])))), \`*\`(0.94045968e11, \`*\`(\`^\`(x[1], 2), \`*\`(x[3]))), \`*\`(46901.078, \`*\`(\`^\`(x[1], 2))), \`*\`(0.70616015e11, \`*\`(x[1], \`*\`(\`^\`(x[2], 2)))), \`-\`(\`*\`(0.13072873e12, \`*\`(x[1], \`*\`(x[2], \`*\`(x[3]))))), \`-\`(\`*\`(994642.52, \`*\`(x[1], \`*\`(x[2])))), \`*\`(0.41170263e11, \`*\`(x[1], \`*\`(\`^\`(x[3], 2)))), \`-\`(\`*\`(2768390.4, \`*\`(x[1], \`*\`(x[3])))), \`-\`(\`*\`(0.22189949e11, \`*\`(\`^\`(x[2], 3)))), \`*\`(0.67100205e11, \`*\`(\`^\`(x[2], 2), \`*\`(x[3]))), \`-\`(\`*\`(961344.42, \`*\`(\`^\`(x[2], 2)))), \`-\`(\`*\`(0.52533380e11, \`*\`(x[2], \`*\`(\`^\`(x[3], 2))))), \`*\`(2309741.6, \`*\`(x[2], \`*\`(x[3]))), \`*\`(0.23373385e11, \`*\`(\`^\`(x[3], 3))), \`-\`(\`*\`(2708629.4, \`*\`(\`^\`(x[3], 2)))))})`

however its elemets is shown correctly

for example the first element is shown as:

x(1) ^ 3 * 0.194986727121702600e10 + x(1) ^ 2 * x(2) * (-0.365391227687975264e10) + x(1) ^ 2 * x(3) * 0.125146284187383199e10 + x(1) ^ 2 * (-0.798715058230362229e4) + x(1) * x(2) ^ 2 * 0.351708738191481209e10 + x(1) * x(2) * x(3) * (-0.414183393126536083e10) + x(1) * x(2) * (-0.918786154503699254e4) + x(1) * x(3) ^ 2 * 0.287889598946906424e10 + x(1) * x(3) * 0.287143252997207219e4 + x(2) ^ 3 * (-0.955947121705965400e9) + x(2) ^ 2 * x(3) * 0.216166802966718006e10 + x(2) ^ 2 * (-0.165522927641286878e5) + x(2) * x(3) ^ 2 * 

Spawned from here. The code itself is perfectly fine, but if the definition of TD is in the same cell with the rest of the code, TD gives an error. The same definition in a separate cell works.

Download td.mw

Any any good programming language or design program the format and style of a document is important for sharing with others.  But for the life of me, I don't know if I'm just missing the painfully obvious, but seriously is there not a blogpost or document about the best writing practices for using maple?

It would be a great help to understand general practices for formatting with the document blocks and execution groups.

How do we print the determinant as a matrix with vertical bars instead of brackets?
Thanks!

mapleatha

Hello people in mapleprimes,

I have a problem about map.

restart;
map(`*`,op([1/x,y,z]));

The output of this code is not y*z/x, but  (x*y*z)^(-y*z).

I can't understand why this occurs.
Can't you teach me about this?

Thanks in advance.

Nov_3_2017_mapleprimes.mw

This is in matlab.  How can we do this in Maple?  Or what is the similar command fft2 in Maple?

Hi,

How do i set up a Fourth order Runge-Kutta, RK4, routine to solve this nonlinear second order differential equation?:

• a=-2, b=1
• k=0.1
• x0=2
• from t=0..100

Do you have any good examples that is similar to this problem?

thanks

So I encountered a Chini differential equation which is solvable in terms of an implicit function

restart; assume(nu > 2, beta > 0, lambda > 0, delta > 0, y >= 0);
simplify(dsolve(beta+y+(D(h))(y) = nu*((lambda+beta+y)^2-delta*h(y))^(1/2)));

The answer is really too ugly to be pasted here, but I do get a
RootOf [ linear + log(linear) + delta* some integral + 2 * the very same integral]

It took me a quarter of an hour to deciphre that the integrals are the same and that I could get it all down to (delta+2)*integral. Because Maple did not simplify it. 

But if I copy what is inside the RootOf(), and paste it into a simplify() - then it does! So how to force it into doing that in the first place? 

Still novice, yes ... 

Hello guys, I have a problem using simplex, at linear exercises.

Example:

> Typesetting[delayDotProduct](with, simplex, true);
> minimize (4*x1+3*x2+5*x3,{x1-2*x2+3*x3>=-1,x1+x2-x3>=1},NONNEGATIVE);

And I got an error:

Error, Got internal error in Typesetting:-Parse : "'_Inert_DELAYLESSEQ' is not a valid inert form"

How can I solve this? I'm new in Maple software. I'm using Maple15.

Thank you, have a nice day!

restart;
unames();  # first call ok
unames();  # second call

Error, invalid input: Typeset:-Kernel expects an equation for keyword parameter numericformatting

Error, unexpected result from Typesetting

Hi,

I want to define an operator P, which can shift the first subscript of u(i,j)

P: u(i,j)->u(i+1,j)

and similarly,

Q: u(i,j)->u(i,j+1)

I am not familiar with the commands in maple, please help!

Thanks.

I have a polynomial of 4th order and I wanted to use allvalues on the RootOf expression. It then says:
 

Error, (in evala/Normal/preproc) reducible RootOf detected.  Substitutions are {RootOf(4678560000000000000000000000000000000000+(16573041*CO^2+70122975000000000000*CO-623180900000000000000000000000000)*_Z^4+(-19887649200*CO^2-82987335000000000000000*CO+745755960000000000000000000000000000)*_Z^3+(5966294760000*CO^2+23851989000000000000000000*CO-221858784000000000000000000000000000000)*_Z^2+(417684600000000000000000000*CO-757598400000000000000000000000000000000)*_Z) = 600, RootOf(4678560000000000000000000000000000000000+(16573041*CO^2+70122975000000000000*CO-623180900000000000000000000000000)*_Z^4+(-19887649200*CO^2-82987335000000000000000*CO+...
Error, (in allvalues) numeric exception: division by zero

So apparently the expression is reducible but how do I do that?

I'm working with Fourier Transform. I'd like to transform a noisy image to the frequency domain, create a grayscale version of the spectrum, mask the dots or lines, threshold it, multiply the binary mask image with the magnitude image and then transform back to the spatial domain. Is this possible using Maple?

Any help would be appreciated.