# All Questions

3 views

### Multiple dynamic equations for plotting?

Say I have a bunch of equations between variables e.g. a=bcd, d=bc, e=bda and I want to do a plot between any two of them, is there an easier way than just rearranging by hand and then plugging into ...
24 views

### Use the trigonometric identities to expand and simplify if possible

Use the trigonometric identities to expand and simplify if possible. A, cos(270∘−θ) B, sin(270∘−θ) C, cos(270∘+θ) Here is my answers, it needs checking. 1. cos(270 - theta) = cos( 180 +90 - ...
58k views

### Where can I find examples of good Mathematica programming practice?

I consider myself a pretty good Mathematica programmer, but I'm always looking out for ways to either improve my way of doing things in Mathematica, or to see if there's something nifty that I haven't ...
81 views

### How to make hollow octahedron 3-compound?

I would like to remove facets from a graphic - like on the picture below. Link I tried to combine these two graphics: ...
24 views

### Interpolating a polynomial for with first and second derivative of points

I am trying to fit a polynomial for switch cutoff which is used in Molecular dynamics. I want a fifth order polynomial with six coefficient $c_0, ...,c_6$ between $r_1<r<r_2$ with these ...
3k views

### How to handle NDSolve::ndsz problem (singularity problem)

I have 2 second order differential equations (non-linear). The physics behind them is correct. I verified the equations many times. It is a solid pendulum with a mass-spring at the end of it. Now, ...
42 views

### Help with the plot f(x)=2ln(-0.5x+2)-1

I don't know how to write equation in the notebook. The graph doesn't appear when I tried.
35 views

### How can I graph the polynomial function? [on hold]

There is no explanation for the polynomial function. The equation is f(x)=-2x^2-4x-3.
125 views

### Coordinate free differential forms package

I am looking for a package in Mathematica which can handle differential forms in a coordinate free manner. I am aware of several packages which do differential forms, but it seems that for all of them ...
104 views

### Obtain polygons describing all intersections of many polygons

I have 6894 polygons describing zones in a state plane (i.e., cartesian) coordinate system. Most are not very complex, and I believe none have holes. A random example is Polygon[{{351633., ...
25 views

### How to keep first observation and delete other observations of each group in unbalanced Panel data

I have a huge panel data. I want to create a new data keeping only first observation of each group. How can I achieve it? For illustrative purpose; ...
35 views

### Copy files existing in different directories under the same directory

I have many files existing in different directories, I need to copy it under the same directory. Any suggestions?
20 views

### Mixture coefficients and Parameter estimation for moving Normal distributions

I am searching for a way to do the following steps below. I am stumped and I have stumped a few profs too. Any help would be appreciated. I would like to import data from, say, excel or a .txt file ...
96 views
+100

### Developing a function of two variables from given data

Cross listed from MSE: http://math.stackexchange.com/questions/1029399/developing-a-function-of-two-variables-from-given-data (I believe Mathematica SE is an appropriate place to ask this, as well.) ...
55 views

### How to tell Mathematica that certain variables are real/imaginary, integer-valued, etc

I'm trying to expedite some quantum mechanical calculations by running them through Mathematica. Expectation values and stuff like that. When I say, for example, ...
38 views

### The use of Evaluate in NDSolve and Plotting the answer [duplicate]

I am having a bit of hard time understanding the use of Evaluate when plotting the output of NDSolve. From the documentation, I enter: ...
27 views

### How do I include assignments inside this?

Noobie question, but if I have this: ...
39 views

### Default color for Filling in Mathematica 9

The default color scheme for plots in my Mathematica version is ColorData[1]. What about for the Filling option?
37 views

### DateListLogLogPlot

The command completion feature in Version 10.0.1.0 shows a command DateListLogLog but there is no documentation and doesn't work. Is this something that is going to be released in the near future and ...
56 views

### Coding While loops

I am interested in replicating the code in this question on MSE, whose contents I have copied for ease of reading: Pseudocode: Consider that 1 is the starting index of a list 1.  input natural ...
52 views

### Make plots of solutions persist

How can the code below be modified so that at allow plots of solutions to persist upon clicking in the slope field. For example, after three clicks, the plots of all three solutions should remain. In ...
117 views
+50

### How to use C language functions in Mathematica?

I'm trying to find out the way to use c-functions in Mathematica (I'm using 14 version) on OS X 10.10. For example I've got this lines of code: ...
170 views

### How to write Morse code into Plot Dashing?

How can we define a dashing pattern in a plot such that it reads arbitrary text in Morse code? For instance Graphics[{DotDashed, Line[{{0, 0}, {5, 0}}]}] ...
64 views

### PlotStyle and Legends

I know only three plot style ...
343 views

### Camel hump string split

Given System names of 2 or more characters: systemNames = Names["System*"] // Select[StringLength[#] > 1 &] ; Is ...
38 views

### What extrapolation method does Interpolation use by default?

As far as I can tell, Interpolation uses cubic spline interpolation by default - please correct me if I'm wrong. What does it use for extrapolation outside of the ...
52 views

### How to embed a filled Region in a Graphics?

Let for example: regn = RegionDifference[Rectangle[{-2, -2}, {2, 2}], Disk[{0, 0}, 1]]; The only documented way I found to draw a gereric region ...
21 views

92 views

### AstronomicalData not including units?

I like using mathematica to do my physics homework, and AstronomicalData is useful for that, but it doesn't seem to work properly with units. [the question is, at ...
138 views

### Combining solar system planets orbits and positions in Graphics3D and Show

I am building an animated model of the solar system, where I would like to display the OrbitPaths of the planets along with their ...
312 views

### How to get the distance of Jupiter from the sun?

I am aware of the command AstronomicalData["Jupiter", "Distance"] from which I can get the distance between the earth and Jupiter. Is there any way to use ...
103 views

This code: ...
34 views

### UnitConvert to Electronvolts converts to Electronvolts/Moles

The question probably is clear from the title. When I want to convert a kinetic energy, that contains the Molar Gas-Constant into Electronvolts I get eV/mol. ...
95 views

### Why does LyapunovSolve solve non-standard form?

LyapunovSolve[A,Q] solves the equation $A P + P A^T = Q$ for $P$ whereas the standard form (wikipedia,lecture notes, p.25, linear control systems) of the Lyapunov ...
### How to obtain Padé approximant of $\log(x)$?
Having read this answer on Math.SE, I wanted to try seeing how Padé approximations converge to $\log(x)$. But my first attempt after reading the documentation failed: ...