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92 views

Why TimeSeries forecasts the future value poorly?

On a bank account there are many recurring entrance and expenses. I've managed to import some sample data and to plot it. I can see that there is a quite clear recurring trend (one wage is coming ...
46 views

TagSetDelayed for spotting zero derivatives

I am trying to implement my own differential operator, d[arg_, var_], that computes the derivative of arg w.r.t. ...
31 views

Tracing & Modifying a Function (Replace All) [duplicate]

For the function: f[x_Plus] := Apply[Times, x] f[a + b + c] Out[]= abc This is clear, as the Times is applied to the list with Plus head in f. However, when ...
63 views

581 views

return {} when the function is given {}

I have a function taking an array as argument and giving an output. However, sometimes my argument is {} (the empty array), then how can I get an output {} when my argument is {}? Actually, I want the ...
126 views

Grid with equation numbers

Is it possible to have a grid with DisplayFormulaNumbered in mathematica journal stylesheet so i would have something like this
41 views

Solving an equation: Reduce command produces failure message

I am trying to solve the following equation for c: All variables can only take positive values and c>s. I have tried the following code: ...
28 views

Reduce[expr,vars] behavior when vars are not present

It is officially documented that Reduce should be used like Reduce[expr,vars]. However, I've used ...
35 views

Arrange a polynominal

I have a complex polynomial in more than ten line. I want to rearrange it by the power of another polynomial. For example, I have a powers of (1-A(x)/x^2) as a factor in it, and I want to sort the ...
35 views

LaTeX/Markdown in notebook

I know that there is the wonderful MaTeX, which is a third party package, but is there a way to duplicate the Jupyter notebook functionality, where one can have ...
112 views

Find gridlines in image of blots arranged in a grid

I have an image with a grid of equal separations. I would like to detect the lines in this image. I tried with ImageLines in but it does not work. @MelaGo Thank ...
138 views

Interpolation[] gives negative values when all the initial data is positive

I have this data: ...
44 views

Quickly restoring default notebook display color and font

(Not a duplicate. I've checked How to "undo" SetOptions (restore defaults)? and others.) Suppose I change some display options, e.g.: ...
25 views

What kind of performance should I expect out of Eigensystem using FEAST?

I'm numerically solving a time-independent Schrödinger equation using Eigensystem's FEAST method. It takes a lot longer than I ...
34 views

How can I always get one option of coordinates of the points A, B, C, D, and X of the Problem 6 in IMO 2018?

This is the Problem 6 of IMO 2018 https://www.imo-official.org/problems.aspx I use the code at Mapleprimes (with some prepairs) https://www.mapleprimes.com/questions/228162-How-Can-I-Get-One-Option-...
51 views

Abs[]^2 , Conjugate[], ComplexExpand[], and Simplify

I think this is a numeric problem but would like to see where it occurs. I create a complex rational polynomial as follows and make it a function of f ...
58 views

Replace function and its derivatives by zero

If I try to replace the function u0 and its derivatives by zero in the following examplary expression ...
46 views

Defining dilogarithm with branch cut on $(-\infty,1)$

If my logarithms have a branch cut on $(0,\infty)$ then the dilogs constructed from these have a branch cut on $(-\infty,1)$. Is there a safe way to implement this in Mathematica? I tried with ...
60 views

Geometric transform of a plot with legends and title

I'm doing a ternary phase diagram, so I want to plot it in a triangle and not in a square. If I'm doing the transformation with legends it doesn't work, but if I don't put legends it does work. Why ...
38 views

Formatting of exporting

I am writing notes via Mathematica, but when I want to share it with others, there exists two problems. First, if I export it as pdf, there is no word wrapping of math expression: and input code: ...
63 views

Two animations on the same ListAnimate plot

I have a code that produces two lists to be animated using ListAnimate and I want to have these two animations taking place on the same plot but I can't see a clear way to do this and was wondering if ...
586 views

modulo with n instead of 0 without using if-statement

Is there a way to to express the following without using an if statement, but with mathematical operations instead? { 5 if x % 5 = 0, x % 5 otherwise }
66 views

Generalization of code is slower than particular case

I wrote the following Mathematica module: ...
90 views

Creating tables with Do command [closed]

Why when I perform this code am I not producing tables called roots[j], each containing 3 elements which are the roots of the equation? When I type roots[0] for example I get about 100 answers for z ...
71 views

Typing and derivating unevaluated sums

First I would like to get the output of F[x_, y_, k_] := Sum[x^(m - n)*y^m, {n, 0, k}, {m, n, k - 1}] as an unevaluated (symbolic) sum. Then, derivate F ...
97 views

Why does not Rasterize work in SciDraw?

In the documentation, it says " Rasterization is requested with Rasterize->True, and the resolution can be specified through the ImageResolution option. " However, when I try to enable ...
I am trying to compare two functions on the end points of an interval. For instance, $f_1(t)=t^3$ and $f_2(t)=t^4$. From my code below I check whether $f_1(t)\leq f_2(t)$ when $t=50$ on $[50, 51]$ ...