# All Questions

153 views

### Area enclosed by two functions

i want to calculate the area percentage of a function in a certain regime above a constant threshold. For example: f[x] = sin[x] x² from 0 to 2 with a threshold ...
252 views

### Permanently set options such as metric units for W|A queries

Mathematica lets me be so lazy that I don't even have to switch to a browser to check the weather report: The only problem is that it will automatically display the temperature and wind speed in ...
102 views

### ToExpression an array

I have a .dat file. I would like to convert a big array of strings(that's what I havein the .dat file) into an array of numbers, for example ...
469 views

### Prevent FullSimplify from converting trigonometric expressions to exponential

There's an option for FullSimplify, which is Trig, and with it I could prevent a trigonometric identities from being used. I'm ...
254 views

### Mathematica can't minimize a function

Mathematica seems not to be able to minimize this univariate function over integer arguments, $r>2, r \in \mathbb{Z}$. ...
77 views

### Controlling output of graphics, the role of “;” and code structure/formatting

";" is described under Compound Expression as a delimiter, such that only the output of the last item in the compund expression is given. Situation: 1/ Print[] produces output whether followed by ...
293 views

### Importing web page data

I tried importing a webpage using Import: ...
97 views

### Reading Options from DateListPlots with legends

Normally I can recover the options used on a DateListPlot easily with Options[]. However if one of the options said a Legend should be attached, it appears all the options are then unreadable. For ...
78 views

### Write memory usage to file in script

Is there a way to write the MemoryInUse into a file once a minute? In this Debugging memory leaks question there is a neat dynamic diagram showing the MemoryInUse over time. My problem is that I run ...
40 views

### Output of the comand Put

I have a do loop in which I "Put" a ListPlot of a list in every iteration by doing Put[ListPlot[list],"file"] While the process is running and is still not ...
136 views

### NDSolve in exact points - nonlinear equation (Degrees and Radians confusion)

I found solutions of two nonlinear equations, but I have three small questions. First I am in confusion because of initial value. The system is mechanical and unknown ϕ is an angle, which I set to ...
982 views

### Mathematica won't simplify the expression with obvious common factor of a fraction

I have an expression obtain from an integral, which is: Integrate[ϵ^2/Sqrt[(ϵ - u)^2 + Δ^2], ϵ] // FullSimplify The denominator and numerator of the result have ...
228 views

### Sample of the random times at which the random walk crosses the boundary

I defined a security boundary for a random walk: ...
67 views

### Maintaining postfix convention for directives in notebooks

It seems to be a fairly common convention to write certain 'meta' functions in postfix form like f[x] // Simplify to keep the the mathematical content at the ...
730 views

### Asymptotic expansion

I wanted to expand a function of $x$ about $x=\infty$ and see its coefficients as a function of the parameters $m,n,q,y$ and I wrote this - but it didn't work! It gave me back a very complicated ...
849 views

### FrameTicks and Ticks on Axes in Same Plot

I have a plot where I would like ticks shown on both the axes and the frame, with them labeled separately. I have custom labels for the frame and want the horizontal axis labeled with ticks ...
443 views

### Revolve A Function Around the Y axis? [duplicate]

I am seeking to revolve the are between the functions function $d(x) = Exp(x)$ and $e(x) = 4 - x^2$ around the line $x = 2$. I am using RevolutionPlot3D, so I ...
726 views

### Alternating sum

A frog is at the bottom of a 30 metre well. Each day it climbs 5 metres up the side, but it then slips back 3 metres each night. How long does it take to reach the top of the well? Is there an easier ...
320 views

### Fitting triangular function with HeavisideTheta

I have a problem fitting a triangular function (like potential vs. time in cyclic voltammetry) with a HeavisideTheta function. I just want to get used to ...
116 views

### nonlinearnodelfit with a matrix as weights

I have to fit a non linear model to my data and I am trying to use nonlinearmodelfit. The problem is that I have systematic errors, so the ...
142 views

### how to load packages on local computer when using remote kernels

I usually works remotely using kernels on our hpc and front-end on my local laptop. This enable me do relatively large computation within my laptop(IP address of my laptop may change frequently). But ...
325 views

### Combine two DateListPlots and retain a time axis

I am trying to combine two DateListPlots to produce a single chart with 2 y-axis. There is an example here with regular Plots and I have tried to adapt it for time based data ...
126 views

### Change Ticks in PairedBarChart

I am using the PairedBarChart feature as follows: PairedBarChart[Range[5], Range[5], BarOrigin -> "XAxis"] How can I (i) remove and (ii) change the number ...
486 views

### Returning a value from a Module

In the following simple example MyMod := Module[{i}, Do[ Return[1], {i, 3} ]; Print["test"] ] I expected the module to exit on ...
406 views

### Base 2 Tick Labels for ListLogLogPlot

I am using ListLogLogPlot and would like to express the x-axis tick labels in powers of 2 instead of the default powers of 10. Does anybody have experience with ...
146 views

### Numerically solving an ODE for a parameter

My equation is as follows: sol = ParametricNDSolve[{(f'[r]^2 - 1) f'[r] r == 6.2 (f'[1])^2/1000, f[1] == a}, {f}, {r, 1, 3}, {a}] where the function ...
99 views

### How to get diagonal matrix D from matrix multiplication of $s^{-1}$, P, and S

I am multiplying three matrices that should give me a diagonal matrix but instead of zeros for the other entries I get very small numbers. Can someone explain what is going on here and how I can fix ...
425 views

### Map of Swedish regions?

There have been some questions dealing with how to draw individual US states since such data doesn't come with Mathematica through its CountryData which offers ...
2k views

### when is f@g not the same as f[g]?

I have always thought that f@g will give the same result as f[g] in all cases, and it is just a matter of style which one to use ...
419 views

88 views

### Why can I edit only one character of the output of a Dynamic expression?

Try this: DynamicModule[{foo = \[Placeholder]}, foo] Note how we're able to edit the placeholder in the output, e.g. replace it with 42: ...
203 views

### Intersection of any triangle with a circle in Cartesian coordinates

I started a notebook dealing with metrics in a triangle and its intersection points by a circle. Up to know I reached the point of having plotted a triangle, a circle with an arbitrary centre and I ...
165 views

### Calculating derivatives of roots of equation

I am interested in calculating how the roots of an equation change as one of the variables does, when the equation is evaluated numerically rather than symbolically. I have edited this code to be ...