# Learn Math

##### Plot The volume of a cylinder between a cone and XY
I want to plot the volume of a cylinder between a cone and the plane XY The equation of the cone is zz == √x2+y2\sqrt{x^2...
##### Interpreting P-Value on ParameterTable
When using LinearModelFit[] we can generate a table of parameter values and statistics for the corresponding model using the property “ParameterTable”. Looking in the documentation...
##### Manipulating List?
I have a huge list with 1000 elements. Manually entering and calculating SUM of probabilities it would take a few hours. Example: list = {1,...
##### PlotLegends in ListPlot does not display different markers
I would like to plot a graph with the legends at its side. However, I have managed to plot the legends, but the markers do...
##### FindMinimum function does not produce minimum from near point
Using my simple program and I would like to find such matrix elements that minimize difference of their eigenvalues. H1 = {{1, 2}, {3, 4}};...
##### Table of ParametricPlots crashes Kernel
I can usually crash the Mathematica Kernel by using Table to generate a List of ParametricPlots, as follows: testpara[α_] := ParametricPlot[ { {Cos[θ], Sin[θ]}, {2...
##### Plot The volume of a cylinder between a cone and XY
I want to plot the volume of a cylinder between a cone and the plane XY The equation of the cone is zz == √x2+y2\sqrt{x^2...
##### Interpreting P-Value on ParameterTable
When using LinearModelFit[] we can generate a table of parameter values and statistics for the corresponding model using the property “ParameterTable”. Looking in the documentation...
##### Manipulating List?
I have a huge list with 1000 elements. Manually entering and calculating SUM of probabilities it would take a few hours. Example: list = {1,...
##### PlotLegends in ListPlot does not display different markers
I would like to plot a graph with the legends at its side. However, I have managed to plot the legends, but the markers do...
##### FindMinimum function does not produce minimum from near point
Using my simple program and I would like to find such matrix elements that minimize difference of their eigenvalues. H1 = {{1, 2}, {3, 4}};...
##### Table of ParametricPlots crashes Kernel
I can usually crash the Mathematica Kernel by using Table to generate a List of ParametricPlots, as follows: testpara[α_] := ParametricPlot[ { {Cos[θ], Sin[θ]}, {2...
##### Animation of a plane wave
I want to animate in 3D the plane wave sin(ωt+kx+ϕ)sin(ωt+kx+ϕ)\sin(\omega t+kx+\phi), but following the form from the documentation, I can only make kkk or ωω\omega...
##### Removing solutions which are particular cases of others
I have an algorithm which gives me a list of solutions (in matrix form, if it is of any importance) of an equation. Some of...

## RSolve: Recursive function is not a valid variable

RSolve[{ g[n + 1] == g[n] + 10*(g[n]*Cos[-10 Degree] – y[n]*Sin[-10 Degree])/ Sqrt[(g[n]*Cos[-10 Degree] – y[n]*Sin[-10 Degree])^2 + (g[n]*Sin[-10 Degree] + y[n]*Cos[-10 Degree])^2], y[n + 1] == y[n] + 10*(g[n]*Sin[-10 Degree] + y[n]*Cos[-10 Degree])/ Sqrt[(g[n]*Cos[-10 Degree] – y[n]*Sin[-10 Degree])^2 + (g[n]*Sin[-10 Degree] + y[n]*Cos[-10 Degree])^2], g[0] == 100, y[0] == …

## Use Do to evaluate an expression over two indices i≠ji≠ji \ne j (over a list of tuples)?

I have an expression of the form: expr1[i_,j_] = Sum[\[Beta][j]*\[Phi][i, j]* C[i] I would like to evaluate this expression over i=1:4, j=1:4 with i!= j. One way of doing this is to evaluate this expression over a list of tuples, say: A = {{1, 2}, {1, 3}, {1, 4}, {2, …

## How to speed or help Solve[] when it is stuck?

The code below generates a system of equations that I need to Solve[] for {c[5], c[6], c[7], c[8]} in terms of {c[1], c[2], c[3], c[4]}. f[x_] := E^-Sum[a[i]*x^i, {i, 0, 4}]; zeroEq = {}; Do[Do[ zeroEq = Append[zeroEq, Expand[D[f[x]*x^n, {x, m}]/f[x]] /. x^r_ -> c[r] /. x -> c[1]], {n, …

## How can I plot bollinger bands on financial time series? [closed]

I can’t find any options for this in CandlestickChart[], but it’s a pretty basic measure, is it not supported? ================= ================= 1 Answer 1 ================= TradingChart[{“GOOG”, {“Jan 1, 2015”, “Apr 30, 2015”}}, FinancialIndicator[“BollingerBands”], PlotLabel -> “Google Stock Price \[LongDash] 2015”] You can alter the paramters, e.g, FinancialIndicator[“BollingerBands”, blah, yada]    …

## Add a portion of a unit circle

Consider: a = {9, -5}; u = a/Norm[a]; Graphics[{ Blue, Arrow[{{0, 0}, a}], Red, Arrow[{{0, 0}, u}], Text[Style[““, Blue, Background -> White], {9, -5.4}], Text[Style[ ““, Red, Background -> White], {1.5, -1.5}] }, Axes -> True, AxesLabel -> {x, y}, PlotRange -> {{0, 10}, {-6, 0}}, GridLines -> {Range[1, 10], …

## How do I partition a matrix?

I have a data file with fields x y z. When I import it to “data”, I get a matrix if the form: {{193.303, 601.595, 0.001079}, {193.383, 612.928, 0.000071}, {199.129, 476.9, 0.000828},..,{199.21, 488.223, 0.000761}} Now z is a function of (x,y) that I need to interpolate. Also, the data (x,y) …

## List Operations: how to combine two lists (pattern given)

Two lists (matrixes) are given: a = {{x1, y1}, {x2, y2}, {x3, y3}}; b = {{u1, v1}, {u2, v2}, {u3, v3}}; Expected return: c = {{{x1, u1}, {y1, v1}}, {{x2, u2}, {y2, v2}}, {{x3, u3}, {y3, v3}}} Please, help to solve this. Useful references are also welcome. Added: duplicates ================= …

## A puzzling result of the ReplaceAll [duplicate]

This question already has an answer here: Why is ReplaceAll behaving like this? 1 answer I tried to do something below Log[PDF[NormalDistribution[m, s], x]] /. Log[u_[x__] ] :> Plus @@ Log[List[x]] which gives a desirable result that splits the expression into pieces. Note that PDF[NormalDistribution[m, s], x] was evaluated of …

## Can one upgrade versions directly from Mathematica front end?

The copy of Mathematica I use I get through work. Upgrading this copy is always I time-consuming, pointless chore. I think all of it could be automated. Which makes me wonder: Is there any way to upgrade (at least from one minor version number to the next) directly from the …

## Trouble fitting with NonlinearModelFit

I’am having a bit of a headache comparing the results from the NonlinearModelFit to a particular dataset. I have the following dataset, data = {{0.1, 4.00159}, {0.2, 8.22197}, {0.3, 0.992585}, {0.4, 1.00674}, {0.5, 0.831299}, {0.6, 0.780187}, {0.7, 0.87409}, {0.8, 0.910718}, {0.9, 1.11082}, {1., 0.88152}, {1.1, 0.742595}, {1.2, 0.691634}, {1.3, 0.768007}, …