# All Questions

150 views

### Intelligent vertex placement in large tree graphs

This question about graph layout is fairly general, but can be illustrated in the case of the Collatz Conjecture. Collatz created the following function over integers greater than 1: If the integer ...
137 views

This is a minor point but annoying. I have just upgraded to version 10.0.2.0 and discovered that you must select a bracket before doing Alt+1, or Alt +7 to make a cell a heading or text cell. This was ...
101 views

### Filtering Query Nested Data (Dataset and Association)

I am trying to filter a nested Dataset. I have some data that looks like this (curated for this example): ...
194 views

### Transform an InterpolatingFunction

I'd like to transform an InterpolatingFunction from NDSolve but can't figure out how. Here's an example. The equation I want to solve is ...
135 views

### Organizing Wolfram language symbols with Entity

Here's a word cloud tally of the ~5k System names split at camel humps, with the long tail cropped. What resources are available to organize these terms using the new ...
191 views

### Manipulate in Manipulate

Question 63982 (Altering values in Manipulate with dynamically generated controls) got a very interesting answer from @belisarius, in which he used a Manipulate ...
338 views

842 views

### Why isn't autosave enabled by default?

While I've come across several ways to implement/enable autosave (see: Is there a notebook autosave frequency configuration?, Saving my code before cell evaluations: Insurance against front end ...
280 views

### Disk is displayed distorted in plot

What is the problem with my plot? I want to get a disk shape. ...
250 views

### Row Alignment in Grid

I've been working on creating tables of differences in MAA similar to the image below, but with a bit more detail: I've written a function that will take an anonymous function, a range of values ...
2k views

### Removing zero values from ordered pairs

I have some processed data, which are basically a collection of ordered pairs in the form: {{x1, y1}, {x2, y2}, ..., {xn, yn}} Ordered pairs which have either a ...
664 views

### Show doesn't show all the plots

I try to combine three list plots with the Show command. Here is the first one: ...
652 views

### What can I do to eliminate the error FindFit::nrjnum:?

I am testing the "Power Law with finite-time singularity" hypothesis for world population growth for a project. The data I'm using (same behaviour should also be exhibited by the stock market, thats ...
481 views

### Interrupting package evaluation, handling error

I have some packages/scripts that I schedule the execution using Jobs in SQL server. For example, in some of then, I use to create reports and delivery by mail using Mathematica. All done using ...
3k views

### How can I solve this PDE with initial conditions?

I wish to solve the following second order partial differential equation $$u_{tt}=c^2 u_{xx}$$ with the initial conditions $$u(x,0)=e^x,\quad u_t(x,0)=\sin x$$ In Mathematica, I evaluated the ...
254 views

### Question on operator: // N

I've seen a notebook with the following: ...
287 views

### How can I colorize an imported model?

How can I colorize an imported model from for example 3ds max? I'm trying to find the way to colorize a 3D plot from an imported model with something like this: ...
359 views

### Eliminating functions from system of PDE in Mathematica

Mathematica users, Let's see an example of three PDEs: How can I eliminate variables q1[x,y,z] and q2[x,y,z] from a system of ...
205 views

### How do I get a list of digits for a number?

I have this 200 digit number where I want to get the IntegerDigits, but the decimal point is in the way. ...
247 views

### Notebook manipulation to “Save as (HTML)”

In a previous question, I said that I wanted to display code as text in "Save as (HTML)". I am closer, but would like to ask the community for a better approach by telling the whole picture. I did my ...
755 views

### Replace expressions by self defined symbols

I have a list of expressions like the following: ...
290 views

### presenting a real number as real instead of imaginary

I have an equation which results in an answer of the form $\frac{i a}{\sqrt{c-d}}$ is there any way to get Mathematica to present it in it's real form? like $\frac{a}{\sqrt{d-c}}$ I know that I ...
323 views

### Path queries for tree-structured data

Can anyone suggest documentation or tutorials for developing path queries and indices for (XML-like) tree-structured data? Suppose data is organized hierarchically in key->value pairs, eg: ...
393 views

### Can SetDelayed (:=) be compiled?

Is it possible to put an If statement as below within a compile (see below)? I received a warning about SetDelayed. ...
202 views

### Setting a lower limit on calculation time

Sometimes it can come in handy to set a lower limit for a calculation. Consider for example an animation that is generated by some infinite loop, which would run way too fast to display properly for ...
903 views

### MaxSteps and Computing time issue for Solving Differential equation in Mathematica

When we solve differential equation numerically using NDSolve then sometimes we get error like NDSolve::mxst: Maximum steps reached According to Mathematica docs ...
148 views

### How to assign symbols to functions

Several functions work with symbols in MMA: Take for example Part: l1=l2=Range[4]; l1[[3]] (*3*) l2[[4]] (*4*) I want to make ...
163 views

### Adding noise to nonlinear ODE system

I have a problem with adding a noise to 3d order ODE nonlinear system. I solved the system numericaly and got the periodic solution and now I need to add random pertubations. Due to the lack of ...
99 views

### How to simplify exponents of the form $\exp\left(i\frac{2\pi}{N}(N+1)\right)$ inside a function

I'm really annoyed with Mathematica and I need your help. I defined a discrete Fourier-Transformation(I use II instead of N, because Mathematica wont let me-.-): ...
98 views

### Evaluation of Derivative in a Module

Can someone help me understand the evaluation procedure in the following two pieces of code? ...
86 views

### Why is the Spherical Bessel Function acting strangely at this point?

I'm doing some computation that requires the use of Spherical Bessel Functions of the 1st kind, at high orders and values. So, I managed to find this, while running it over a wide range of values. I ...
### Approximate $h$ in $F(\theta)=\sin \theta \int_{-L}^{+L}h(z)e^{-ikz\cos \theta} \,dz$
Consider $$F(\theta)=\sin \theta \int_{-L}^{+L}h(z)e^{-ikz\cos \theta} \,dz$$ $$|z|\le L$$ $$0 \le \theta \le \pi$$ By having knowledge of $F(\theta)$, how can one approximate $h(z)$? In ...