# All Questions

94 views

### Defining a function that that evaluates a function to obtain a value not supplied as an optional argument

I have a function like this CentralDifferentMethod[α_, β_, α1_, α2_, λ_, v0_, dt_, t_] Now, I want to add a new parameter ...
112 views

### Rearranging 5 equations

I am trying to rearrange 5 equations in terms of 5 variables. I have the equations for y1, y2, ...
117 views

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297 views

### How to draw multi curves in a graph with errorbars

The curves are composed by several 2*n nested lists. I want these curves be placed in a 3d way, like the xy plane is for the data, different curves are located in several parallel xy planes with ...
74 views

### Import file size capacity for Mathematica

I am trying to import a large data set (.csv) into Mathematica. The data set contains more than 14 million rows, is this something Mathematica can handle? If not, what is the maximum capacity? I have ...
73 views

### How to solve this equation?

Mathematica does not give me the correct solution (-1) for this equation: Solve[9^(x + 4) == 27^(1 - x), x] Do I miss something or is Solve the wrong approach ...
276 views

### Approximation to the prime counting function

Is there a function similar to PrimePi that gives approximate value for large numbers? In particular, I need a reasonably good approximation for $\pi(x)$, where ...
77 views

### How could I visualize a rotating cone within a sphere?

I am just learning Mathematica and as the title states here is what I want to achieve. How do I visualize a rotating cone within a sphere ? The length of my cone is governed by following equation. ...
131 views

### How can I restore the old ImageCompose behaviour?

Prior to version 10, if ImageCompose was used to overlay a partially transparent image region over a completely transparent image region, the result would keep the ...
74 views

47 views

### distributing definitions in an .m file and memory

I am dealing with a huge table stored in an .m file of size 4 GBs. Somehow when I call the table in .nb file it seems the memory increases not by 4 GBs but more than 10GBs (roughly checking from task ...
57 views

### NMaximize not substutiting parameters of objective function [duplicate]

NMaximize is not substituting parameters of its objective function. Is there a way to fix that? I have a three line program that exhibits the problem. ...
111 views

### Possible bug / numerical issues with HypergeometricU — any suggestions for a fast workaround?

I've encountered some problematic behaviour with HypergeometricU. I have a probability distribution on the positive integers that takes the following form after ...
71 views

### How can I create a set (list) provide a kind of rule/algorithm?

Example: S = {r ∈ Q : r² < 2} Let S be the set of all rational numbers whose squares are less than 2. It follows that 1 ∈ S, 4/3 ∈ S, but 3/2 doesn't ∈ S because 9/4 ≥ 2. Thank you.
182 views

### Graph expansion on Mathematica

Is there a way by which Mathematica can be given a graph as an input and be asked to find its expansion? Note: By "expansion" I mean the quantity called "isoperimetric number" or "Cheeger constant", ...
128 views

### NSolve for complicated equation involving double cross product

I have the following issue. I am trying to solve a 3-vector equation for the vector slx, sly, and ...
402 views

### Greek variables in 10.0.1

Bug introduced in 10.0.1 and fixed in 10.0.2 10.0.1 under Ubuntu 12.04 x64 .... Does everybody get greek variables emboldened? Is anybody aware of how to revert to previous normal display? The ...
210 views

### Solution to a T+U = E equation

I needed to solve really easy differential equation (in dimensionless units):  \mathcal{T} (\dot{\xi}) + \mathcal{U} (\xi) = \text{const.} \equiv \varepsilon ; \quad T(\dot{\xi}) = \dot{\xi}^2 ; ...
76 views

### Bug with Initialization in DynamicModule?

In exploring Tracking Initialization, I came across this. The following usually shows a value for x of 300000 to ...
283 views

### How to plot a series using different colors depending on the y-value

I have a sequence of numbers ${x_1,x_2,\ldots,x_n}$. I would like to plot the sequence using ListLinePlot but use a different color depending on if the values $x_i$ are within $a_i<x_i<b_i$. ...
149 views

### Tracking Initialization

How to track Initialization step by step? Any tricky solution is ok. One condition, x should be ...
525 views

### Extracting the function from InterpolatingFunction object

I've used Interpolation[] to generate an InterpolatingFunction object from a list of integers. ...
241 views

### Find all heads a function is defined on

So say I've got a function g defined as follows: g[x_Integer] := x + 1 g[s_String] := s <> "!!!" How would I write a ...
83 views

### How to generate a 3D terrain from a terrain-map image? [closed]

I attempted to generate a 3D terrain from a terrain-map image with the following code. What I got was a NULL terrain. What is wrong with my code? ...
918 views

### An inverted pyramid

I want to draw a pyramid approximately like this ...
147 views

### How to multiply specific columns in a matrix of data?

So I need to make a plot of some ~2000 data points I have from a spreadsheet. I'm able to import the data just fine, it stores it like so sundat ...
260 views

### Solving a system of two nonlinear equations with many symbolic parameters

I have two nonlinear equations with two unknowns, $x$ and $y$, and many symbolic parameters, $a, b, c, d$. They look someting like: $\frac{1}{x}(1+x)^a (1-b)(cx+dy)=0$ ...
302 views

### How to SemanticImport Multiple Excel Sheets

I have an Excel workbook with multiple sheets that I'd like to import into a dataset each. With Import I can target individual sheets by their name into a nested ...
202 views

### Vertical (mis-)aligning of plotmarkers and legend text in V10 PlotLegends

Consider this example, taken from the docs and modified for a larger font size using Style (V10.0): ...
196 views

### Interpolation on an unstructured (mostly-structured) grid in 4D+

I frequently need to perform interpolations on an unstructured grid. Mostly, with the purpose of filling grid holes and then later continue with regular grid interpolations. Mathematica V9 and V10 ...