Questions about the use of built-in Mathematica functions, including pure functions.

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-1
votes
1answer
83 views

How to specify a specific range for a loop?

I'm having trouble with setting up a particular range in a loop for my programming. Now I have a defined range of data (not continuous numbers) that needs to be applied in a loop. Since the aim for my ...
2
votes
4answers
227 views

Find time since last 0 in list

When I have a list of data (measured per day), is it possible to define a function that gives the nr of days since the data has been 0? I tried working with...
1
vote
1answer
87 views

Circumventing the default scoping: Assign a variable inside a function [duplicate]

I'm currently trying very hard to assign a variable inside a function. Therefore I'm using a function like this, which should reassign a predefined variable. ...
1
vote
1answer
204 views

FindMaximum inconsistency

The code below seems to work for n<11. But for n=11, and above, it outputs newa then just outputs "beep" sound. WhyTheBeep says "The kernel Local has quit ...
1
vote
1answer
237 views

Notebook UI: Autocompletion - Display function arguments when typing?

Is there a setting to display the required arguments of a function when typing as Visual Studio, Matlab, etc. does?
8
votes
1answer
128 views

Strange behaviour of Internal`InheritedBlock

I was going to post an answer for fast way to replace all zeros in the matrix. I was even quite happy because timings were the same order of magnitude as others. The idea was to overwrite ...
0
votes
0answers
58 views

Display functions without dependence?

I'm solving systems of equations with a few different functions of time, t, and so I'm getting output with lots of [t] running around. Is there a way to display these functions without the ...
1
vote
2answers
178 views

Add a column to a matrix as a function of the other columns

I was wondering if its possible to add a column to a matrix by a formula that uses all other columns, like this: ...
0
votes
2answers
841 views

Defining a function in terms of matrix elements

Currently trying to use elements from a matrix in defining a function however having some trouble. This is a somewhat simplified version of the problem. Say I have the matrix ...
0
votes
1answer
44 views

Showing result of derivative and other functions [closed]

I have a problem with my Mathematica 7.0 When I write: Derivative[x^2, x] Mathematica returns as result : ...
15
votes
2answers
952 views

Why do certain values in ArcSin not fully evaluate?

This is a continuation of: Why do certain fractional values in TriangleWave not evaluate? The analysis by R.M and rasher revealed that problem to reduce to the behavior of: ...
1
vote
1answer
194 views

Is linear interpolation applicable here

From my understanding about Linear Interpolation especially of that of Newton's Divided Difference Polynomial, we could get the value of F(x) from the given set of ...
0
votes
0answers
21 views

Incorporating Built-In Function Options/Parameters into Shorthand [duplicate]

Shorthand syntax provides an alternate way to apply functions and, in many cases, improves readability. A simple example would be ...
0
votes
1answer
63 views

Extend a function defined for integers to a differentiable function of a real variable

Here is a function that calculates the probability of randomly landing on a Fibonacci number not greater than $n$: ...
3
votes
1answer
179 views

The UnitStep function and Intervals

For the input UnitStep[Interval[{-4, 5}]] I get Interval[{0, 1}] Why is this not ...
3
votes
0answers
51 views

Precedence of defined functions [duplicate]

When I define functions in Mathematica like: f[x_] := 3 f[x_Integer] := 6 How is the value of f[6] determined? It seems to ...
7
votes
5answers
355 views

Is it possible to insert arguments into functions when they're used like Function@ or //Function?

Is it possible to insert arguments into functions when they're used like Function@ or //Function? Sometimes I need to do this, but then I have to return to the standard function usage: Function[] ...
3
votes
4answers
261 views

Redefine ArcCot to be inverse of range [0, Pi]

Mathematica implements ArcCot function as an inverse to Cot on range [-Pi/2, Pi/2]. I ...
9
votes
2answers
435 views

Nest , Fold … is there an extension for more than 2 arguments?

Fold is an extension of Nest for 2 arguments. How does one extend this concept to multiple arguments. Here is a trivial example: ...
2
votes
1answer
160 views

Piecewise function with user-input interval

I would like define a function g[data,bins,x] which is a piecewise constant function taking value data[[i]] in the range ...
1
vote
2answers
210 views

How to sort Table/Matrix including legend(Labellings)

I want to sort table including its legend for graph I have table similar to M1 M2 M3 1 5 2 3 1 4 4 2 -10 5 7 11 6 -2 1 ...
6
votes
2answers
259 views

Why does PolynomialQ[x^n, x] return False?

From what I can see PolynomialQ will return False whenever some exponent is another variable such as here: ...
10
votes
4answers
857 views

Refering to global variables inside modules

How do I refer to global variables inside modules if the same name is used for a local one? In code, I want that ...
1
vote
3answers
211 views

professionalize/optimize my code that calls a function

I have the following construction, which defines a function that I subsequently call in a loop multiple times. I use this very often, but I have never looked into if there is a more professional way ...
6
votes
3answers
378 views

Understanding Function and Variable in Mathematica for beginner [closed]

I'm reading the book of Leonid Shifrin, and I love the way the book explains the core in Mathematica. As everything is an expression, now I understand that, there ...
3
votes
0answers
149 views

Do a gauge transformation for a Chern-Simons theory?

Suppose we have the following Lagrangian density: $$ L=\epsilon^{\mu\nu\rho}\big(\sum_a A^a_{\mu}(x) \partial_\nu A^a_{\rho}(x)-\sum_{a,b,c}\frac{1}{3} f^{bca} A^a_{\mu}(x) A^b_{\nu}(x) ...
1
vote
1answer
119 views

Transform list of inequalities into matrix form $A\ x \leq b$

I have a list of linear inequalities, and I want to get it into the form $A\ x \leq b$; i.e., find the matrix $A$ and the vector $b$. Is there any function in Mathematica that can that can do this?
0
votes
0answers
43 views

Limits of PrimeNu [duplicate]

Is there any way to find distinct prime factors for very large numbers using Prime and/or PrimePi that exceeds the ...
2
votes
2answers
89 views

`PrimeNu` counting function

Building on this question, what is the most efficient counting function for distinct prime factors? It would obviously be more efficient if Prime and ...
0
votes
2answers
147 views

How to calculate expected return, row by row in matrix? [closed]

Please help me, I'm writing my project and dont know how to solve this big matrix: I have to compute return row by row: 1st row: (18.32-17.14)/17.14 ; (19.17-18.32)/18.32 .... ...
1
vote
1answer
74 views

Defining functions that reference other values

How could I define a function that references other values? eg a = 2 x; b = 4 k; f[k_, x_] := a^b
8
votes
4answers
369 views

Numerical instability in cosh and sinh - integral functions [duplicate]

I'm trying to calculate the function: CoshIntegral[x] Sinh[x] - Cosh[x] SinhIntegral[x] Unfortunately Mathematica seems to hit a point (x~20) and things become ...
8
votes
2answers
263 views

Automatically compute r[1] = r1; r[2] = r2; …

I have three variables like this, r1 = 4; r2 = 3; r3 = 1; and I want to insert them into a function use them in a function definition like so: ...
1
vote
1answer
119 views

Linearity of a function in Mathematica

I have a function which has something like myFunc[q,a state[c,d]] a could be anything, and I want to tell Mathematica that ...
1
vote
1answer
147 views

Function derivatives in arbitrary dimension

I have a higher dimensional function: $$f(x,t)=-\ln(t)-\ln(1-\left\|x\right\|^2-t^2)$$ where $x\in\mathbb{R}^n,~t\in\mathbb{R}$. I want to compute the derivatives with the commands ...
4
votes
3answers
308 views

Prime factor counting function

Is there any way I can speed up this prime factor counting function? (I am looking for all numbers in a range with 3 prime factors (counted with multiplicity).) ...
4
votes
2answers
190 views

Using Element[]

Can the Element[] function only be used for the domains given in the documentation? I am trying to use it to determine if a value is contained in a previously defined list. Thanks!
1
vote
3answers
216 views

Pure function inside another pure function

I have the following working expression: In[15]:= Length[Select[IntegerPartitions[10],First[#1]==5&]] Out[15]= 7 But, instead of using the constant 5 I want ...
5
votes
3answers
2k views

Make a differentiable smooth sawtooth waveform

So, I am trying to understand the effect of sawtooth waveform on a mechanical system model. For example, a system of a plate and a box on it. And then we try to oscillate the plate. In order to do ...
6
votes
1answer
590 views

How to type binomial coefficient $\binom{n}{k}$

I know how to type a fraction as you would write a fraction in Mathematica (9). How do you type Binomial[n,k] as $\binom{n}{k}$ in Mathematica? Is there a single ...
-1
votes
2answers
239 views

How can I extract when a select condition is met in a do loop the value of the iterator?

I use the following code to find out the number of consecutive prime numbers using a formula $n^2+n+i$ found out by Euler (starting from n=0): ...
17
votes
2answers
4k views

Is there an equivalent to MATLAB's linspace? [duplicate]

Does Mathematica have an equivalent to Matlab's linspace? I want to make a list with "start", "stop" and "number of points". What is the neatest way of doing this?
0
votes
2answers
254 views

Using a table to format a grid

Ok, I can't wrap my head around this because I don't know Mathematica well enough yet, so I'm asking for help, at least a direction to explore in. I have a Grid: ...
4
votes
1answer
169 views

Volume within parameter space

Imagine a parameter space with variable 0<p<1, 0<e1<1/2 and 0<e2<1/2. ...
3
votes
3answers
383 views

How would I plot the volume element in cylindrical coordinates?

I have this graph: But it doesn't have a function so I can't just plugin in a function into wolfram or mathematica to plot it. I have these coordinates to make it however: ...
4
votes
3answers
638 views

Multiple output cells

Is it possible to have multiple outputs from a single function? For example: In[1]:= x+1 x+2 Out[1]= 1+x Out[2]= 2+x has multiple outputs, how can I ...
2
votes
2answers
1k views

Q-Function representation in Mathematica

I observed that there is no Q-function representation in Mathematica. The definition of Q-Function is: \begin{align} Q(x) &= \frac{1}{\sqrt{2\pi}} \int_x^\infty e^{-\frac{u^2}{2}}du \\ ...
4
votes
1answer
213 views

Orthogonalizing without normalizing

Is there a way to make Orthogonalize do the normal Gram-Schmidt procedure without normalizing the result? As far as I've understood this was possible with ...