# All Questions

2k views

### Error entering equation in DSolve

I entered a command incorrectly as follows: DSolve[{y'[x]=y[x]},y[x],x] I am now experiencing: ...
874 views

### Why does piecewise plot have a discontinuity when the function, first and second derivatives are equal?

There were some related questions to this one, but in this case we have the function value, the first derivative and the second derivative all equal (that was actually the problem I was solving). We ...
219 views

### Hide function arguments (from unknown functions) for simpler output [duplicate]

How can I print my expression with my function's arguments hidden? For example: exp=A[r,z]+B[s]^2; HideArgs[exp] Output: ...
93 views

### Circumventing the default scoping: Assign a variable inside a function [duplicate]

I'm currently trying very hard to assign a variable inside a function. Therefore I'm using a function like this, which should reassign a predefined variable. ...
226 views

### Ugly plots when printing notebook to pdf

One image is worth one thousand words, so: Question: At what options should I be looking, so that what I see in my notebook is what I get in my printed pdf ? Here is the code I'm using: ...
144 views

### Possibility of evaluating the expression within a NestList at each iteration?

I want to rotate iteratively a triangle about the same point, increasing for each iteration the length of its side in the same proportion and change the color of its sides. I came up with the solution ...
262 views

### User-defined usage message template; removing repeated text

In Mathematica 9.0.1, I want to write a user-defined template for a function that I wrote: myfunc ...
372 views

### Using Locators in a non-standard Manipulate code

I'm trying to adapt Nasser's method for using a control variable inside Manipulate to selectively choose what part of the code should be recalculated depending on the controls changed (see this ...
366 views

### Unable to Solve Two-Point Boundary Value Problem

I'm trying to solve the equation -u''[x] + ((x - k)^2 - en[x]) u[x] == 0 using the boundary conditions ...
243 views

### Using Manipulate with a control variable for selective recalculation

I'm trying to adapt Nasser's method for using a control variable inside Manipulate to selectively choose what part of the code should be recalculated depending on the controls changed. I've also read ...
451 views

### Using units and piecewise functions in Integrate

For simple cases, Quantities appear to be handled well by Integrate: ...
519 views

### DensityPlot Increase Information

I am trying to make a density plot in Mathematica, however the distribution of the plot is not as visible as I would like. I plotted the same function in python and it contains a greater visible range ...
1k views

### Trying to graph trajectory function in Mathematica? Won't Graph?

The exercise is: Define the trajectory function y(x) in Mathematica. Pick the initial speed (in meters per second) equal to ...
112 views

### Simplifying using assumptions

Is there a way to simplify the following equation (-p(a-x)((a-b)P(b-x)+Q(b+x)(a-b+2x))+q(a+x)(-(a-b)Q(b+x)+P(b-x)(-a +b+2x)))/((b-x)(-a + x)(a+x)(b+x)) assuming ...
2k views

### List manipulation: position & max value combination

Starting with {{0, 0, 0}, {1, 1, 2}, {2, 3, 3}, {3, 4, 5}} I would like to get {{0, 2, 3, 5}, {1, 3, 2, 3}} where the ...
317 views

### MapThread multiple functions onto multiple lists

I'm trying to learn the functional style which seems to prevail in Mathematica. I'm having trouble accomplishing the following: Let's say I have multiple lists of arbitrary data (using two lists ...
332 views

### How to make a big image/dashboard containing various data-graph

I want to make and image/dashborad (to export to PDF) with many VERTICAL bullet graphs gauges. And I can´t make it, in a automatic way. In general, the questions are: QUESTION 1: How to make a ...
426 views

### Unable to solve a set of equations with Solve

I'm trying to solve the following equation using Mathematica 9.0.1.0 : ...
424 views

### Counting 'False' values at the ends of a list

I have table like this: t = {False, False, False, 4.5, 6.789, 1.23, 0.98, False, False} and I want to know how many False values I have at the beginning and at ...
128 views

### Reflecting the Polya-Aeppli distribution

How would I go about reflecting the Polya-Aeppli distribution in Mathematica about a y-axis (switching left and right) while keeping the command. The distribution will not allow negative parameters ...
629 views

### How to write a variable in terms of the other [duplicate]

I have an equation that defines a variable like y=4x+a. I had another equation, z=x+2+4, I would like to know if there is a way in Mathematica to get an expression in which z= a*y+C, in which a and C ...
775 views

### Breaking up long equations in TeXForm

If I have a horrifically long expression and output it to TeX using TeXForm, I get a long equation which needs to be split up into multiple lines. But splitting it up manually can be quite cumbersome. ...
125 views

### How to Check Spelling strings written inside input cells

Is it possible to check the spelling of strings? Strings are often used to show messages in my user interfaces, and I would like to have an automatic checking. Methods that export all the strings to ...
450 views

### How to test whether an expression is a valid variable?

I would like to test whether an argument is a valid variable for functions like Solve and DSolve. For instance several ...
193 views

### Why BarChart3D plot of Mathematica 9 is not working similar to Mathematica 7 version?

Mathematica 7 Needs["BarCharts`"] BarChart3D[{{1, 6, 8}, {2, 7, 1}, {3, 1, 4}}] While in Mathematica 9 it is not plotting in this manner. Please help me to ...
349 views

### Replace rule with function? Derivatives don't evaluate

Say I have an expression (call it expr) involving a function, f[x]. I'd like to be able to evaluate that for a particular choice of ...
154 views

### How to break graph to fill in the gap in pdf

I've printed my notebook into a pdf. There is a huge gap in the left page, due to the fact that the graph in the right page isn't divided to fill in the gap. Is there a way to fix it, preferably ...
122 views

### Strange results of definitions using OwnValues

I am asking this question simultatenously with this one, which is strongly related. I was trying to see if I could create the behaviour as in that question without using ...
303 views

### Another difference between Set and Setdelayed. Evaluation shortcut?

A little while ago I wondered why f[x_] = f[x] gives an infinite iteration. I ended up discovering the following difference in evaluation between ...
144 views

### Graphics Function Definition Style (Using SubValues vs. DownValues)

I am going through some of the items in "Modern Differential Geometry of Curves and Surfaces with Mathematica, Third Edition". An example of the style used by these authors is: ...
175 views

### Using DeleteCases with multiple AstronomicalData properties

I am attempting to use AstronomicalData and DeleteCases together to remove invalid cases of two properties while listing the ...
978 views

### Replace symbols with values without evaluation

If I have assigned values to a, b and c: ...
208 views

### Simplify equation using conditions/inequalities

If I have an equation like f[x](1 + a)==0 I'd like to be able to tell Mathematica that 1+a doesn't vanish in general, and get back ...
822 views

### Arbitrary precision spline interpolation

The current implementation of Interpolation does not allow arbitrary precision spline interpolation. Yu-Sung Chang says here that "it is not hard to implement it ...
66 views

### Display functions without dependence?

I'm solving systems of equations with a few different functions of time, t, and so I'm getting output with lots of [t] running around. Is there a way to display these functions without the ...
28 views

### Possible bug while plotting homographic function with stylled axes (?!) [duplicate]

Seems like a bug to me, don't have time to dig more now. WinXP V9.0.1.0 ...
131 views

### Computing lists using AstronomicalData

Edit: Initially in my question I asked how I could search the database of AstronomicalData["Exoplanets"] and return 2 filtered values that only contained valued ...
870 views

### Fourier Series of “Split” Defined Function

Not sure how to phrase this in a concise way, anyway it seems like the function FourierSeries assumes the interval for which to compute the Fourier coefficients of a given function is $[-\pi,\pi]$, ...
299 views

### Filling only part of a plot [duplicate]

I have something plotted on [-6,6] but I would like to fill only the part from [-5,5] (to the axis). I'm looking through the documentation but I'm not terribly well-versed in Mathematica and can't ...
348 views

### Draw only part of axis in graph

I'm looking to draw only one half of an axis in ContourPlot3D, mainly because I don't wan't the axis lines to be where the interesting stuff happens (intersection ...
283 views

### Graphing convolutions of user defined functions

I am a statistician who is very new to Mathematica. Ultimately I would like to be able to graph convolutions of arbitrary user defined functions. But I can't as yet obtain values of such ...
2k views

178 views

### Associate the elements of a table

I have a table form as: table = {{a, 6}, {b, ff}, {c, 2}} I want to associate the first element of each pair from the table to the second element of the pair as ...
77 views

### Extract information from functions that returns nested structures with DefineDLLFunction

Where can I find examples devoted to extracting information from functions that returns nested structures with DefineDLLFunction in Mathematica? The only example I found and understood, was given by ...