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

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0
votes
1answer
80 views

Working with functions

I am required to write a function that takes a function as a parameter. ...
1
vote
0answers
30 views

How to apply an rule to factors matching a certain form

Suppose we have many expressions involving irrational ArcTan expressions (such as ArcTan[Sqrt[3],5]) along with other irrational factors (such as ...
3
votes
1answer
67 views

How to apply RootLocusPlot corectly

I have to analyze the complex regions of variable c which is define obtained with InverseLaplace help in the form ...
0
votes
2answers
152 views

How can I improve Do loop?

I have very large input of time series data (over 30000 observations) that look like as follows: ...
0
votes
1answer
49 views

How to define a function that operate with a base case recursively? [duplicate]

Let's start from the simplest case: say I have a function $f(x)=x$, and let's say I want to define a new function (of $x$) to be its $n$-th power $(f(x))^n$. How should I write the code? I tried: ...
3
votes
2answers
188 views

Differential operator squared

I defined a one-dimensional momentum operator $\hat{p}=-i\hbar\frac{\partial}{\partial{x}}$ in Mathematica p = -I * h * D[#, x]& and I want to get the ...
2
votes
0answers
56 views

Are there some other ways to solve a second PDE except DSolve?

I have a partial differential equation as follows: $$\frac{\partial p(x,t)}{\partial t}=\text{Dp} \frac{\partial ^2p(x,t)}{\partial x^2}-\frac{p(x,t)-\text{p0}}{\tau }$$ What I try to do was to get ...
0
votes
0answers
96 views
2
votes
1answer
74 views

Arguments for ChartElementFunction

I was reading the documentation for BubbleChart and I saw this example ...
0
votes
3answers
75 views

How to combine multiple functions into a single function, indexed bya new argument

I have a system of expressions (matrices) which correspond to increasing orders of precision in a theory. These expressions are quite complex (require about 40+ lines of code to produce) and are not ...
1
vote
0answers
62 views

Slow mixture fitting when having ill-conditioned covariance matrices. How to make it faster?

I'm using Mathematica 9.0 to fit multidimensional observations with a gaussian mixture. To do so I first adapted these steps to ensure that the mixture parameters are well defined (see ...
5
votes
2answers
318 views

Multiply each element of an array by another array?

I would like to multiply an array by each element of another array, and am having a lot of trouble finding a built-in or automated method of doing. Here is an example of what I'd like to achieve: ...
1
vote
2answers
56 views

Using Array Elements as Function Arguments

Suppose I have an array p = {a,b,c,d} and a function f that takes a variable number of arguments. I want to evaluate ...
0
votes
1answer
50 views

Can I make a function which depends on several arguments which are not independent?

Here's a simple example Suppose have the permanent relation that z is proportional to xy^2, for real numbers s. z = s x y^2 Now, we are interested in ...
0
votes
0answers
27 views

Problem with slot in If statement [duplicate]

I am struggling with slots, In this case I have a function int which gives either true or false. When it gives true, I want ...
1
vote
1answer
157 views

Interpolation of a table with 4 parameters

I have a huge data file which I need to do some analysis on it. The file is built in this way that for each 4 variables, there is a value of the function: ...
8
votes
1answer
131 views

Why does Plot[Hold[x], {x,0,1}] work?

It appears that, counter to my expectation, all of these (and probably many others) seem to work fine: ...
2
votes
2answers
209 views

How to plot several functions without jumping? (multiple eigenvalues of a system as functions of 2 parameters)

I've been working on this research problem for months with some success by no global/proper solution to the problem. So I have square, Hermitian matrices of various sizes ($8,20,38$ dimensions) with ...
2
votes
0answers
89 views

How is Wolfram Language different than regular Mathematica? [duplicate]

From all I can see there seems to be no difference between "Wolfram Language" and regular Mathematica. Is Wolfram just a marketing rebranding of Mathematica or is there a new capability I am missing?
12
votes
4answers
318 views

How to make a function with its own options as well as passing options to other functions

I have a function with many of its own options, but I would also like to pass options to subfunctions using the FilterRules function. Here's a simple example: ...
11
votes
1answer
287 views

Better Autocompelete for the Front-End

I wonder if it is possible to improve the front-end's autocomplete capability. Compared with some other more sophisticated editors/IDEs, such as eclipse, Mathematica's front-end does not provide a ...
5
votes
4answers
208 views

Using an ellipse as a threshold for Nearest function

The Nearest function can receive as a threshold parameter a radius to look for elements inside that. From the documentation: ...
0
votes
0answers
55 views

Fixed Point Math in MMA

I am working with a library that needs input in a Fixed Point notation. I’d like to figure out a way to convert the floating point results into fixed point representation. The fixed point length is ...
0
votes
1answer
49 views
6
votes
2answers
95 views

Partial result of aborted evaluation of FullSimplify

When FullSimplify invoked on a large expression, it can run for hours. If I do not have time to wait, and abort the evaluation, I get no result, although, ...
0
votes
1answer
154 views

Please explain this code (contains Append, Do, Coefficient)

I am a graduate student using a past student's Mathematica program. Will someone please explain to me exactly what this piece of code is doing? Specifically the ...
0
votes
1answer
73 views

Log is not being evaluated inside Grid [closed]

My command is: Grid[{{N, logN!, N log N - N}, {10, Log[10!], 10 Log[10] - 10}}, Frame -> All] In the second row of the grid, the function ...
2
votes
2answers
51 views

Why is left NumberPadding always applied in NumberForm?

I would like to display numbers like 9.0001 and 10.0001 in the fixed-width form of xx.xxxx. ...
0
votes
1answer
75 views

Finding equation of tangent line at a point [duplicate]

my function is defined as f[x_] = x^1.1 - 2.5 x^.5 I need to find the equation of the tangent line to the curve using the point slope form which would be something like f'[a][x+a]+f[a] a=1 and x=1 ...
0
votes
0answers
21 views

Question about a ParametricPlot with a shading grey family of lines and/or different sizes [duplicate]

So, I have this function of the polar angle $\theta$, with a varying parameter $t$: {Cos[\[Theta]] (1 + Sin[t]), Sin[\[Theta]]} and I want to draw it in a ...
2
votes
2answers
78 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 ...
4
votes
0answers
102 views

Can Mathematica Operators be combined in a linear fashion for readability?

Here's a simple example. Suppose we want to find the off-diagonal matrix of m: m={{1,2},{3,4}} This can be solved fairly simply by extracting a list of the ...
3
votes
2answers
255 views

Define a function with a function for an input

I want to create the functions $even[f]$ and $odd[f]$ which will apply the formula $even[f(x)] = \frac{f(x)+f(-x)}{2}$ and $odd[f(x)]=\frac{f(x)-f(-x)}{2}$ for an arbitrary $f$. I tried using ...
20
votes
1answer
372 views

What is PointForm?

I stumbled across a function called PointForm but the only documentation I can find is the pop-up line offered by autocomplete, which contains the same information ...
1
vote
1answer
92 views

Perform FindRoots on Function Evaluation Containing RootSearch

I am using Ted Ersek's RootSearch function in Mathematica 9.0 (http://library.wolfram.com/infocenter/Demos/4482/) to create a function that I am using for graphing. ...
5
votes
2answers
203 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
146 views

Is it possible to convert expressions containing Root objects to Excel formulas?

I am still a beginner and do not fully understand pure functions and root objects. When I tried to calculate the inverse of a function, Mathematica gave me: ...
1
vote
2answers
145 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. ...
1
vote
1answer
75 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
120 views

Pass unevaluated function with evaluated arguments

I am almost sure that this question has been asked somewhere. I found similar ones, but I cannot find exactly what I need, which might mean that I am on the wrong track. I search a method to pass an ...
0
votes
0answers
41 views

Using Table[ ] vs using Do[Append [ ] ] [duplicate]

Is it generally better/faster to use the Table function over using Do[Append []]? For example, I have this piece of code: ...
2
votes
1answer
479 views

How could I define a function as the solution of equations in Mathematica?

I have posed a specific question yesterday but it may be too trivial to answer. I think the question could be asked in a more general way so it is easier to answer. Then I could solve the original ...
0
votes
1answer
70 views

How to write series of Do[ ]'s with a single Table[ ]?

Edited to provide more information (sorry I don't know how to format matrices here) I would like to replace: m = 4; ...
3
votes
1answer
204 views

Help on how to write a function to be used with NMinimize

I need some help to write a proper function to be used as a parameter on NMinimize. Here is the code of the function to be minimized (Please correct, optimize and rewrite the code if you want to - I ...
0
votes
0answers
68 views

Using Reduce on an inequality

I have been evaluating this formula, $\frac {3^r - 1} {2^r - 1}$ for $r>1$. The numerator is always even and the denominator is always odd. I am trying to show that the denominator will not ...
0
votes
0answers
49 views

Generating Suffixes [duplicate]

I am doing a large Matrix calculation in which I need to generate symbols first like $F^{\mu\nu}$ I would like to get $\mu\nu = 00, 11, 22, 33$ and so on. I need to have the symbols before I can ...
6
votes
2answers
162 views

Evaluation in lambda function

If I have a function, that returns a function, for example: f[a_] := a^2 * # & then f[3] == 3^2 # & Is there a way ...
1
vote
1answer
85 views

How to define a summation with function calling itself?

I am new to Mathematica. I want to do this f(x)=summation f(t), summation is over t, where 1<=t<=x-1 and mod(x+1,t+1)=1, i.e. when x+1 is divided by t+1, remainder is 1 and f(1)=1. Should i use ...
4
votes
5answers
866 views

How to sum over a List

list = {11.5575, 11.397, 5.52734, 4.0878, 2.54815, 1.86652, 2.55028, 2.14952, 1.6242, 1.34117} I have a list of numbers. How do I make a function that creates a ...
0
votes
0answers
32 views

How to plot image of a complex function with a given domain [duplicate]

I've been trying to figure out a way to either draw a curve in the domain of a complex function in one plane and then show the result in another plane (simultaneously?). Actually, just plotting ...