1
vote
1answer
139 views

TabView switches tab number without user input in first evaluation

I've attempted to use TabView in a Manipulate to display sets of controls and alter a "display" associated with each set of ...
0
votes
1answer
284 views

Exporting tables of interpolating functions

A few weeks ago I asked a question about manipulating parameters in NDSolve (Looping with NDSolve?) , and received some very helpful advice about the manipulate environment; now I want to take the ...
0
votes
0answers
73 views

Preventing numeric constants from being pulled out of square roots

If I input Sqrt[2 g], Mathematica automatically pulls out the 2 and returns Sqrt[2] Sqrt[g]. ...
3
votes
1answer
541 views

How to get rid of all complex numbers and functions?

For almost esthetical reasons, I always have been fascinated by infinite sums of series and I always wonder if theyhave a closed form. A couple of days ago, I found on MSE a question related to the ...
-1
votes
1answer
284 views

Multiple NIntegrate (again)

Basically I have the same question as here: Multiple NIntegrate but since I don't have enough "reputation" I cannot comment there. I want to solve the following multiple Integral numerically at given ...
1
vote
3answers
281 views

Conditional Check on Matrix

Suppose I have the following matrix (i,j): ...
0
votes
0answers
119 views

Back Linear Substitution

I have an equation set Ax=b and A(n*m),n<m . To lower down the dimension, I express some vars by other vars, which gives ...
2
votes
2answers
1k views

Line of best fit on LogLog plot

I have a LogLog plot, and i'm unsure about how to fit a line to it. The data represents a calibration curve. ...
4
votes
1answer
250 views

Changing Plot order for 3D printing

Alright, I got a my first 3D print done of a pseudosphere using parametric plot and a deflated sphere using a contour plot, but when I try ...
6
votes
2answers
248 views

Fundamental Theorem of Calculus for definite integrals… assume continuity?

So here's the problem: I can evaluate the indefinite integral: Integrate[D[u[x], x], x] u[x] However, I'd like to ...
20
votes
1answer
290 views

Performance regression for Fold?

Bug introduced in 8.0 and persisting through 10.1.0 or later I noticed an over 10x performance drop on Mathematica v9.0.1 (as Oleksandr R. commented, also v8) compared with v7.01 for this code: ...
3
votes
2answers
466 views

Convert number to exponent form with highest power possible

As a school assignment we have to write a program which solves this issue. Since the program has to run efficient I am wondering what the best way is to approach this issue. Of course there you can ...
0
votes
0answers
31 views

Use Map with OptionValue [duplicate]

Trying to map OptionValue to a list of option names doesn't work. ...
0
votes
0answers
22 views

Manipulating named patterns inside replacement rules [duplicate]

When I evaluate the following expression, {a -> "value1", b -> "value22"} /. {Rule[x_, y_] -> Rule[x, y]} I get ...
12
votes
1answer
180 views

What are the differences between library call back functions and WolframCompileLibrary macros?

I'm trying to use LibraryLink in Mathematica, and come across some problems. Consider if we have a MTensor m1 which contains a one dimensional double array, and I ...
4
votes
0answers
120 views

Establish connection with RLink and Rtools

Has anyone gotten RLink to work with Rtools (or even tried)? If so a simple step-by-step would be much appreciated ! When attempting to access any Rtools functionality through RLink I get: The ...
2
votes
1answer
103 views

How to extract a variable names (not values) from a list of transformation rules?

I am trying to extract variable names from a list of transformation rules mapping = {var1 -> 'val1', var2 -> 'val2' }. Variables ...
1
vote
1answer
254 views

How to do Inverse formulas/Rearrange formulas in Mathematica? [duplicate]

Hi am a student in chemical engineering and I have the necessity to rearrange formulas algebraically, for example ...
0
votes
0answers
158 views

Maximum of NDSolve output. Problem with interpolating function

I solve a NonLinear PDE and get a solution (which for other reasons I put into a vector): SolVec1[1][[2]][x,t], where x and t are the indipendent variables. Now, I would like to get a distribution ...
2
votes
1answer
670 views

Why does Mathematica evaluate Sin[2.0] but not Sin[2]?

I can't understand why is it that In[88]:= Sin[2] Out[88]= Sin[2] while In[89]:= Sin[2.0] Out[89]= 0.909297 I even tried ...
1
vote
1answer
792 views

Plot Fourier transform of $\sin (2 t)$

I'm trying to plot the Fourier transform of $\sin (2 t)$. I tried using the FourierTransform Function (I'm expecting a peak at w = 2) but it gives me undefined at ...
5
votes
2answers
783 views

Quickly calculating the mean / median of a function over an interval

I'd like to calculate the Mean or Median value of a function over some interval $[a,b]$. However, I can't seem to find how to do this in help. Specifically I'd like to have something that works like ...
0
votes
1answer
334 views

Using NDSolve for three variables as function of time

I want to be able to plot z, and r. Should I be using DSolve, NDSolve or something else? I've tried to clear it up a bit Thanks, Will ...
1
vote
1answer
155 views

How to change the format of FrameTicks

Here is a plot with the default frame ticks S1 = Plot[Sin[x], {x, -7, 7}, Frame -> True, Axes -> False] Now, if I define myself the range as well as the ...
3
votes
1answer
380 views

Solving Rotational Equations of Motion

I'm trying to integrate the rotational equations of motion ...
1
vote
1answer
101 views

How can I check if one expression implies another?

Say I have one expression, for example $x^3-3 + c = y$, and I want to check if it implies another with some set of explicitly stated assumptions. With the previous example, assuming all variables are ...
0
votes
1answer
73 views

LinearProgramming behavior

Consider the following linear programming problem: ...
1
vote
2answers
495 views

Multiple curves plotted with different colours [duplicate]

I am trying to use ColorFunction for 2 functions on the same plot. I only want the cubic equation to change colour. ...
5
votes
1answer
126 views

Define customised distribution with discontinuous CDF

I have the following CDF: ...
1
vote
0answers
36 views

How do I define a tensor from another tensor with summations? [duplicate]

Let's say we have a rank 2 tensor $g_{ij}$. This is basically a list with a Depth of 2. Now I'd like to calculate another tensor ...
-1
votes
2answers
267 views

Is there any Robotic Package in Mathematica?

Is there any Package in Mathematica that deals with Robotics and their application?
0
votes
3answers
3k views

How to find integer solutions?

Following is the equation: Need to solve for integer values of x,y when a,b lies between -1000 and 1000. Problem is to find the number of integer values of pair (x,y) that satisfy it.
6
votes
3answers
408 views

Finding connected components in an array

I have an $w\times h$ array with non-negative integers. I wish to partition the set of coordinates $(c,r)$ with $1\leq c \leq w$ and $1\leq r \leq h$, in subsets, so that each subset corresponds to a ...
7
votes
1answer
262 views

Variable scoping in Module

I don't understand why $a$ and $b$ are not local in the following code: ...
2
votes
1answer
143 views

Deriving least-squares equations in Mathematica

I define $Y = a + b*x + e$, and I want to find values for $a,b,$ by least squares, so I minimize $RSS = sum((Y_i - a - b*x_i)^2)$ I then take derivatives, ${d RSS \over da} = 0$ and ${d RSS \over db} ...
3
votes
0answers
65 views

Why doesn't ReplaceAll work on Image? [duplicate]

ReplaceAll seems not to reach inside Image, and I don't see why it shouldn't. Here is an example. Create a black and white image ...
3
votes
1answer
247 views

Integrate equations of motion when force depends on position

I'm fairly new to Mathematica. I'm trying to test my C++ implementation of a fourth order Runge Kutta method for Newton's equations of motion. I want to test my integrator when the applied force is ...
0
votes
0answers
278 views

Interpolation of multidimensional data organized logarithmically

The following threads call our attention to the fact that "accuracy of Interpolation will be worse with an unstructured grid", in the context of interpolation of 3d data: interpolation of 3D data ...
0
votes
0answers
17 views

Restoring a Mathematica session without notebook interface [duplicate]

It happens all the time that I close my Mathematica session and later I regret that I have done so, because there are many things that I would like to check. I would like to know if there is a way to ...
5
votes
1answer
402 views

Mathematica scripting on Microsoft Windows

Is it possible to use Mathematica (or the Mathematica kernel) to interact with Microsoft Windows, much like any macro-based scripting language that controls the keyboard/mouse, opens/closes programs ...
0
votes
1answer
106 views

Replicating Excel output using Mathematica

I have 2 columns of data in Excel. One is inputs the other is outputs. I ask Excel to make a graph of that data and to fit the data to a power trendline. Excel does this and it's fine as far as it ...
0
votes
0answers
99 views

Local variable names - Is there an easy way?

I apologize first, because this has been asked, like in Treat all variables as local in a module [duplicate] Variable scope similar to other languages But I don't get how to use them. Some codes ...
10
votes
1answer
3k views

How to solve a system of partial differential equations?

Edit: since the upgrade to Mathematica 10, this problem seems solved I just want to solve a system of partial differential equations, for example: $$ \left\{ \begin{array}{l} ...
2
votes
2answers
122 views

Testing for arbitrary algebraic expression in given variable

I want to test, for example with MatchQ, if the argument of a function is an arbitrary expression in a single or several variables whose names can be assumed to be ...
1
vote
1answer
281 views

Boundary condition is not specified on a single edge of the boundary of the domain

I am attempting to solve a PDE as prescribed in a paper I am reading; however, Mathematica doesn't seem to be happy with the way I am posing the problem. Im my case, r(t,100) is an approximation of ...
4
votes
2answers
107 views

Problem with ViewVector

I am trying to have a satellite (camera) move around the earth (unit sphere) and take picture of the earth. The satellite keeps constant distance from the earth, and always looks toward earth center. ...
2
votes
0answers
82 views

Problem with files size

I need to work with long time series, but I notice that this generates huge files that Mathematica doesn't handle well at all: even opening/saving one of this files is difficult, and the kernel quits ...
0
votes
1answer
75 views

Excluding an interval of parameters from Integrate [duplicate]

I'd like to compute an integral that depends on a parameter, but I'd like to exclude an interval from the computation. For concreteness, say I want to compute ...
20
votes
6answers
3k views

Finding the intersection of a curve with an interpolation function

There are no issues trying to find the intersection points of two defined curves. ...
1
vote
2answers
142 views

Symbolic solution of system

everyone! I am sorry, but I am an abcolute novice of Mathematica (to be more precise this is my first day of using it) and even after surfing the web and all documents I am not able to solve the ...

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