0
votes
1answer
46 views

Adapt the code to produce a three column table containing the values of n, etc. (Numerical integration)

Here is a “procedural” program that we wrote in my class, implementing the rectangle rule of numerical integration: ...
0
votes
1answer
44 views

Minimization Nminimize nnum error

I have imported data (mat is the name, 1x100 dimensional vector)and written a likelihood function for normal distribution. ...
0
votes
0answers
26 views

How to use FindFit to find the parameter in Laplace space(numerically inverting Laplace transforms)

I am trying to find the parameter in Laplace space, and a very simple example is shown below: I have known the solution $y_{laplace}$ in the laplace space is $a/s^2$, and I also have some discrete ...
0
votes
1answer
32 views

Create a Table depending of two variables [closed]

I tried to create a table depending of two variables as: W= Table[{G[[i]], G[[j]]}, {i, 1, 3}, {j, 1, 3}] I wanted it to look like ...
0
votes
0answers
20 views

Problem to solve small polynomial system with real coefficients [closed]

I'm randomly generating some polynomial systems of degree 2 and solving them on Mathematica. These are really "small" polynomials and should be easy to solve them, but still NSolve looks like having a ...
0
votes
0answers
28 views

FileName[ ] doesn't work correctly [closed]

When I call the command FileName[ ], it doesn't give the correct list of files in the directory I've set using SetDirectory. Some files are listed that have been removed, and other files that are in ...
4
votes
3answers
155 views

Periodically tiling a function

I have a function which creates a hole of varying radius, depth and would like to tile it in x and y. ...
0
votes
0answers
37 views

Substitution Permutation Network (SPN) - Decryption In Mathematica

I am working with a Substitution Permutation Function, SPN, in Mathematica. I have an encryption function for an SPN. By changing the parameters that go into the spn function, and not the function ...
1
vote
3answers
137 views

How to calculate time period?

I have the starting and ending dates and times. And I need to calculate the night time in this period (from 10 pm (22) to 6 am (6)). Example: starting date and time is {2015, 1, 4, 3, 10} ending date ...
4
votes
2answers
54 views

conditional expectation doesn't work with SmoothKernelDistribution

I'm trying to calculate a conditional expectation E[ x | x > a ], where the distribution of x is inferred from a finite ...
6
votes
3answers
87 views

Comparing elements of a set and deleting elements based on a criterion

I have a function that has two inputs. The first input is a set of 2-element sets, and the second input is a single 2-element set. My function complements each 2-element set with the second ...
0
votes
1answer
42 views

Block Matrix Multiplication [closed]

I have a = {{-1}, {0}, {0}} b = IdentityMatrix[3] c = {a, b} d = {{7}, {2}, {0}, {0}} and would like to compute e = c.d ...
1
vote
3answers
149 views

Solving differential equation

I want to solve the following differential equation DSolve[y''[x] == (λ y[x])/Sqrt[-1 + x], y[x],x] But do not know how to actually solve it. Any suggestion?
1
vote
2answers
120 views

A shortened association

...
0
votes
0answers
22 views

MatrixForm Output for Block Matrix [closed]

I have a = {{-1},{0},{0}} b = IdentityMatrix[3] c = {a,b} and I would like to use MatrixForm to output c nicely for display. But... ...
0
votes
0answers
39 views

Procedure argument value change [duplicate]

I'm trying to create my own hamiltonian cycle algorithm using Mathematica for school, and I'm stuck on a syntax issue. I get the following error: ...
-1
votes
1answer
48 views

It is possible to calculate a two vector integral

I have this problem: calculate the integral of: -1+Sqrt[2*d+1] with d being a distance of two points in a 60$\times$60 box ...
0
votes
0answers
35 views

Struggling with unexpected recusion [closed]

I'm trying to look at some sequences of functions and collect the values as a list. I had created the following function (without the 'list' part) and it worked fine. I then added in the three lines ...
0
votes
0answers
43 views

Passing integration constants to self defined function

I would like to evaluate an integral I am taking in cylindrical coordinates, in which the integrand contains a previously defined function. I need to pass the r and phi integrand values to this ...
0
votes
0answers
39 views

Using mathematica to to find region of integration of triple integral [closed]

essentially what i want to do is see the region of integration so i can figure out the limits i need to integrate over i am able to plot each bound individually but can put them together to make the ...
0
votes
0answers
42 views

Strange “Collect[…]” behaviour

I have a large expression which I need to simplify by pulling out a load of constant terms. Collecting terms seems to only work when the expression is expanded out, e.g. ...
0
votes
0answers
19 views

NMinimize using NIntegrate functions

I'm looking for a minimization problem. I have a numerical function which is defined through a numerical intregation, which, in turn, have two parameters. The numerical integration is a very demanding ...
1
vote
2answers
73 views

Is there a way to search for Arithmetic Progressions in a list?

If you have a list of integers is there a way of searching that list to see if there is a trend of Ax+B in the list? Not using all of the numbers, just seeing what trends like that are embedded in a ...
1
vote
2answers
43 views

Limit the number of processors used by ParallelTable?

By default, ParallelTable will use all the processors available in a PC. Is there a way to set a limit to the number of processors used by ...
1
vote
3answers
130 views

Find value of x such that x! less than or equal to 1000

I am trying to find the maximum value of $x$ such that $x! \leq 1000$. I tried the following: NSolve[Factorial[x] - 1000 == 0, x] but I got this message: ...
0
votes
0answers
38 views

codes for random rational function [closed]

I am in the extension of getting the expected real roots of random algebraic polynomials, and I'm wondering if I can apply this concept to a rational function. My problem is about the codes. What ...
0
votes
0answers
55 views

Solve[..] does not solve the equation? A bug?

I tried to get the values of CosTheta where the expression is zero and store theses in sol. ...
0
votes
1answer
24 views

How calculate linear conversion based on an input and output range? [closed]

For example I have an input that can be any number, an input range of 2-10 and output range of 0-8. An input of 0 outputs 0 An input of 2 outputs 0 An input of 10 outputs 8 An input of 100 outputs ...
0
votes
1answer
39 views

Finding the intersection of two graphs [duplicate]

I'm having difficulty with finding the intersecting point of two graphs. Here is what I have done so far: Plot[{8*n^2, 64*n*Log2[n]}, {n, 0, 100}] which produces ...
3
votes
4answers
203 views

How to switch from List of rules to Association?

Considering we have a list of rules: ...
0
votes
0answers
93 views

How can I speed up this NM optimization? Most delay seems to be due to long analytic expression

I am struggling with computational speed of a NelderMead optimization. Nevertheless my impression is that I lose lots of speed not only due to the NM optimization itself but rather to for instance ...
0
votes
2answers
82 views

Numerical 3D Integration in Mathematica [closed]

My question in short is: Is it possible to make numerical 3D integration in mathematica efficiently? Or am I gonna have to move this to C++? I feel this problem is way too trivial to go to C++, so ...
2
votes
1answer
51 views

Is there a shorthand for Optional with Condition?

I have a recursive function that does some work to an object for a repeatedamount of times. ...
0
votes
1answer
44 views

Some problems about ListPlot3D, plot 6 faces of a 3D region [duplicate]

I get the data of six faces of a 3D region. ...
1
vote
0answers
37 views

SystemException[MemoryAllocationFailure] with Memoized function

Version 10.1 Win7x64 Enterprise. This is more of a report than a question but others may have seen the same / have insights. I have some code (that I can't really post as it's too big) with a large ...
4
votes
1answer
58 views

? (Definition) versus ?? (Information)

What is the difference between ? Definition and ?? ...
1
vote
1answer
52 views

Plot roots of polynomial system of equations in 3 variables

I have the two equations $x^2 + 2y^2 + z^2 = 1$ and $xz -y^2 = 0$ I want to plot the roots in 3D. i.e the coordinates $x,y$ znd $z$
0
votes
1answer
44 views

Difference between Log and Log10 [closed]

I typed a function : f := Tan[(1/a)*Log[(Sqrt[x^2 + y^2])]] - y/x I assigned values: ...
0
votes
0answers
53 views

Turning Latex into Mathematica code [duplicate]

It is possible to get Mathematica code to Latex alright, but is it possible the other way too, i.e., auto translate Latex back to Mathematica code? If available it could help many users active both ...
26
votes
1answer
321 views

many indefinite integrals do not evaluate in 10.1, looking for the cause

Many integrals no longer evaluate in V 10.1 when they did in 10.0.2 Here are some 23 integrals as an example, that all produced results in V 10.0.2, but now all returns unevaluated! I am hoping ...
0
votes
1answer
84 views

Plotting multiple functions in 3D plot [closed]

I would like to plot the flowing into one 3D region. So I know the region of integration the functions are $z=1-x-2y, z=0,x=y$ I want to have all graphed on $1$ plane so I can see the region of ...
3
votes
1answer
36 views

Apply a list to a summation expression

I've gotten unexpected (at least to my novice eyes) application of a list of values to a Sum expression where the variable for imax is also used in the expression ...
0
votes
1answer
34 views

How to change the radius markers and number of concentric circles in a polar plot?

I'm using PolarPlot to plot a function in [0, 1] in a log scale plot, capped at -40 dB, as in the following example: ...
0
votes
1answer
26 views

How to get the modulus of following complex number

I want to get the modulus of following (1+(x+I*y)/2+(x+I*y)^2/12)/(1-(x+I*y)/2+(x+I*y)^2/12) I use ...
2
votes
3answers
71 views

How do I map a function onto the result of an expression that already has a pure function as an argument

I admit that I have only a basic understanding of the way Mathematica handles pure functions - enough to be dangerous, unfortunately. I have some data that is in a list of lists of lists. I would ...
5
votes
0answers
47 views

FullSimplify Produces Result that Includes Hold

In the course of developing a solution to Question 79183, I solved the equation ...
0
votes
3answers
37 views

Define a function of a vector without fully specifying the components of the vector [duplicate]

I have a vector $A=\{1,2,3,4,5,6\}$, and I want to define a function of $A$ as f[A_]:=A.X where $X$ is another vector. I want to define this function without ...
5
votes
1answer
76 views

Export from ParametricPlot3D to 3D Formats yields distorted surface meshes

as described im my blog post: http://wolfig-techblog.blogspot.de/2015/04/blender-as-shader-for-mathematica.html I tried to export a Klein bottle ParametricPlot3D to one commonly used 3D mesh formats ...
0
votes
1answer
93 views

Building a 1 page “Scorecard” in mathematica [closed]

I'd like to be able to generate an 11 x 8.5 "scorecard" for various data projects I am working on. Traditionally, I'd import all my data into Excel, put the data into worksheets, and then have a ...
6
votes
0answers
89 views

ListConvolve Memory Hemorrhage

I wrote a routine that convolves an impulse response array with a test array and checks for the RMS difference between that convolution and a data array. I do this iteratively so that I can modify the ...

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