# All Questions

483 views

### Exporting row vector as a column in excel

I want to export a vector in Mathematica to appear as a column in Excel. I am trying A={1, 2, 3}; Export["mfile.xls", {"A" -> A}] But it is showing 1,2,3 in ...
208 views

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715 views

### Dataset in Mathematica 10.0.1

Wolfram pages "Mathematica Quick Revision History" in Mathematica 10.0.1 release says: "New operators and compositions of operators enabled for associations functions such as Dataset and Query" ...
100 views

### Is there a way to convert the mathematica document into word document in a neat way?

Is there a way to convert the mathematica document into word document in a neat way? I tried by "save as" command and found something like Risk text format "*.rtf" but still many parts look messy.. ...
173 views

### Display Quantity in full form

Is there a way to display Quantity[] in full form in the output? I know you could use Quantity[valuse, Unit]//InputForm, but ...
72 views

### Why does my Dynamic NonliearModelFit keep running?

I have complex data and which I am fitting to a complex formula. In order to use NonlinearModelFit I split the formula and the data into real and imaginary parts. ...
197 views

### Double integral changing the limits

This integral does not evaluate: Integrate[ Integrate[1/(E^((a - c)^2 + (b - c)^2) ), {c, 0, 1}], {b, -Infinity, Infinity}] However, reversing the integrals ...
160 views

### Building an arch in SystemModeler

I'm trying to learn SystemModeler and struggling a little... Building on the chain pendulum example from Wolfram, I've happily made a chain with revolute joints with spring/dampeners connecting the ...
90 views

### How to set the width of grid elements in pixels?

That is all: How can I set the width of columns in a Grid in terms of pixels instead of 'ems'? To be more precisely, I want to create a grid that is 330 pixels ...
390 views

### Display variable name instead of value

Is there a way to display the variable name instead of its value? for example, I need something likevarname = 1; function[varname]; and the output is ...
197 views

### Variable number of controls in manipulate

i want to add a variable amount of variables to manipulate, but i got stuck at one point and can't figure out a solution (even after reading here for hours...). I have a function (e.g. here a ...
260 views

### Conditional ListPlot with text recognition

This is my data ...
204 views

### How to get the series coefficient of a function defined by a differential equation [duplicate]

I need a Taylor series approximation for $x(t)$, which is defined by the following differential equation. $\frac{dx}{dt}=-k_1 x+(1-x)k_2 e^{-k_3 t}$, $x(0)=0$ ...
75 views

### How to overwrite a private symbol value temporarily?

I have a package file mypackage.m with BeginPackage["FooBar"] Begin["Private"] tmp=2; foo=2*tmp; myprogram[foo] ... End[] EndPackage[] The file is VCS ...
862 views

### Plotting a moving ball for projectile motion with animate

Here is my code for plotting an orbit. What I want to do is have the "planet" shown as it orbits in the simulation. Can anyone help with this? ...
930 views

### Finding exponential model from data [duplicate]

I'm trying to find an exponential model from data for a homework problem. There is an accompanying video explaining how to do the bigger problem but it omits any instructions on the step where the ...
533 views

### Applying a function to a Dataset column conditional on another slot's value

How to apply a function to a column conditional on another slot's value? The Dataset documentation show only how to apply a function to named slots independently. The ...
131 views

### Auto highlighting input cells depending on input expression (eg its Head)

Is it possible to programmatically highlight (eg, by change background color) an input cell conditional on the input expression's Head (or other attributes) upon evaluation? For example, would like ...
243 views

### Can I find constants in a function?

Let's say, I have a function with a constant, e.g. $y(x)=x+c$, and a condition $y(0) = 5$. I want to type in something like Solve[{y[x]=x+c, y[0] =5}, {c}] and get ...
264 views

### How can I resolve the insufficient memory to complete the computation problem for solving function with iterated variables?

I am trying to solve for a value x in a function where the variables varies with iterations of K. Also, there is one variable called "rvsum" which is updated with a certain formula as well. I have ...
117 views

### Why is it not allowed to define vectors of variables in a scoping construct?

The following command assigns 1 to a, 2 to b and 3 to c: ...
236 views

### Import selective elements from mixed (text and numbers) data file

How can I import only the 2nd and 5th elements (numbers, located in the 2nd and 5th columns) from all n raws of a data file (.xlxx) that contains both numbers and text. Imported data be inserted into ...
302 views

### have a function redefine itself as it maps through a list

I have a list which contains sublists, e.g. list = {{a,b}, {a,b,c}, {a,b,a,a}, {b,c}, ...} I then map a function through each sublist. This function should ...
549 views

### drawing core-shell structure [duplicate]

I am pretty new in Mathematica drawing. I am trying to draw a core-shell structure, it means a core sphere with a shell sphere, like this It can be in 2D or preferentially in 3D. Does someone can ...
47 views

### How to call a java method that takes a boolean (not Boolean)?

I'm trying to call a method on a java object that takes a single boolean argument - note boolean (native or primative) not Boolean (Object or Reference type). ...
166 views

### Select in complex dataset query

I want to use Select for a more complex dataset query. Part of the query shall be dynamic, depending on the user input. The Select part looks something like ...
104 views

### How to understand the extensional usage of Flatten? [duplicate]

Recently, I have been reading Mathematica program that written by many advanced Mathematica user, like Mr.Wizard, J.M., Kuba,etc to improve my programming capacity In the On generalizing Partition[] ...
840 views

### Find arc length

I am trying to find the arc length for using ...
252 views

### What is ColorEqualSigns and how does one use it?

I'm setting up the SyntaxInformation for a package I'm writing and I'm struggling to understand what the "ColorEqualSigns" ...
642 views

### Is there a way to rewrite integrals in Mathematica using u substitution?

In Mathematica, can I give it an integral and a few substitution rules and have it rewrite the integral in terms of those variables?
130 views

### Replace $z$ with interpolated function and plotting

I start off with this equation $z(x,y) = sin(xy)$. I create an interpolation from $0 < x < 5$ and $0 < y < 5$. I then use this interpolation on a simple function $w(x,y) = x + y + z(x,y)$ ...
719 views

### Coalition Games

Suppose an election produces the following result: result = {{"a", 120}, {"b", 80}, {"c", 50}, {"d", 30}}; Letters are parties and numbers seats. To form a ...
265 views

### How to propel the integration of time a little bit further? Numerical solution can not evolve to the max time

I try to solve a nonlinear partial differential equation. I obtain a numerical solution which can not continue to the max time I set, I always receive message NDSolve::ndcf: Repeated convergence ...
403 views

### How to specify units for ImageSize Option? [duplicate]

I'm trying out making a CDF and I want it to print within the margins of Letter paper. There is an ImageSize option that I would like to set; some plots will be in ...
230 views

### Coupled Nonlinear Differential Equations Problem

I have a big problem solving a set of coupled nonlinear differential equations using NDSolve. Solving the equations by themselves works quite well but if I want ...
520 views

### How to manipulate a circle in GeoGebra style?

I want to emulate the GeoGebra app. I want to get an effect like this in Mathematica. I don't know how to move whole circle without changing the radius of the circle. My sample code： ...
147 views

### Mapping over an association producing an unexpected result

The documentation for associations says that the keys of an association are transparent for many operations. Map is one such operation. However, I am confronted ...
164 views

### Changing the length of the vectors in vectorplot [duplicate]

I have the following code, and I've tried almost everything I can think of, even VectorColorFunction to describe magnitude. I am trying to make the length of the vectors proportional to r^{-2}, and ...
151 views

### How do I bandpass a signal in Mathematica 8

I would like to use the bandpassing function that is available in newer versions of Mathematica but not Mathematica 8: ...
286 views

### Second order differential equation

Hey guys I need someone to give me a hand on this. I don't know if this is too complicated or it's just the lack of knowledge I have on Mathematica. I'm trying to solve the following equation but ...
462 views

### Maximize violating constraints

I have Maximize[{(h*10)/(300*(100 - (l^.5 + d^.4 + H^.6))), (l + d + H + h) == 669, l > 0, d > 0, H > 0, h > 0}, {h, l, d, H}] I believe ...
387 views

I was trying to solve the initial value problem $$u'(t) = \sqrt{u(t)} + \frac{1}{n+1}, \, u(0) = 0$$ using DSolve: ...
208 views

### Solving with DSolve recursively

I need to find $f(x,n)$ in the interval [0,1] defined by recursion, $$\frac{d f(x,n+1)}{dx} = f(x,n)$$ with boundary conditions $f(0,n+1) = 1$ and $f(x,0)=1+ x$ Using ...
206 views

### ListContourPlot is blank

This is probably very simple. I want to do a simple ListContourPlot. ...
704 views

### Splitting strings into letter keys and integers

I have strings of the following form: string = "ABC123DEFG456HI89UZXX1"; Letter keys of variable lengths are followed by (positive) integers. I want to get this ...
312 views

### Efficient method to generate Tridiagonal 50 by 50 Matrix? [duplicate]

I'm looking to generate a tridiagonal 50x50 matrix, ideally without using loops. Suggestions on most efficient code for this?
252 views

### Incorrect result while using SemanticImport for CSV file import

I might use this incorrectly. I want to use a .csv file that (as list) looks like: ...
1k views

### Generating random symmetric matrix

Suppose first that I want to generate a matrix whose elements are independent and identically distributed (i.i.d.) with distribution dist. This is easy: ...
I have specified just one set of $s$ and $g$ values that yields a real value for the NIntegrate below. It is possible that some $s,g$ combination can give rise to ...