# All Questions

253 views

### Picking numbers within a list with an interval of 60

I have a list of integers from 1 - 400. I choose n random numbers with replacement from the list. Here is an example: ...
474 views

### Problem with Covariance Matrix Output in NonlinearModelFit

I am running NonlinearModelFit based off of some simulated data and trying to fit to a function with more than one parameter. Eventually, I would like to fit to 5 ...
93 views

### what is the difference between these definitions? [duplicate]

I define 2 functions: g[s_][x_,y_] := the gaussian (1) g1[s_,x_,y_] := the gaussian (2) I get the same answer using ...
444 views

### Intersection for lists of numeric data

I know that Intersection is a pattern matching function and will not evaluate list elements to determine if two or more list have equal elements. So my question is, ...
244 views

### Using the keyboard to interactively and dynamically specify coordinates in a grid (a la Battleship board game)

In Mathematica, it is possible to create a Table or Grid of \[Placeholder] boxes. For ...
339 views

### Importing numerical values from a PDF file

I need the numerical values from pdf files like this one. When I use the usual Import command, the PDF imports, but pages of images. How can Mathematica be used ...
205 views

### Unexpected complex roots from solving a cubic

I am new to Mathematica and there is a behavior that I don't understand. When I insert the code: Solve[-(x - 2)^3 + 10 x - 10 == 0, x] I obtain: ...
484 views

### How can I deal with a non-numerical value for a derivative at $t = 0$ when using NDSolve?

I want to solve two coupled equations with NDSolve, ...
181 views

### Trigonometry expansion of a product

The following command does what I want: ...
160 views

### Optimization for inequalities in $\mathbb{C}$

I want to check when the expression $$\sqrt{\sqrt{\lambda^{2}\left(2E+\lambda^{2}\right)}+E+\lambda^{2}}$$ is real, when it is purely imaginary and when it is complex (with imaginary part not ...
550 views

### Optimization problem with matrix positivity constraints

Is it possible for Mathematica to parametrically find a local minimum of a given function (say of some variable $x$ where $(a,b,c)$ serve as parameters) subject to the constraint that a given ...
213 views

### Variable scope in nested NMaximize, NMaxValue

I'm trying to use NMaxValue inside other statements (FindRoot and NMinimize). Those statements should bind variable names, but I'm getting weird warnings which seem to indicate that the variables ...
1k views

### Computing the fundamental matrix and its monodromy matrix

Assume $\dot x(t)=v(x,t)$ is a $T$-periodic, with respect to $t$ dynamical system. That is: $x\in\mathbb R^n,\quad t\in\mathbb R,\qquad v(x,t+T)=v(x,t)$. Let $x_0$ be a smooth periodic solution in ...
451 views

### Using MathKernel without echoing a window

I use M9 under windows 7 on a command prompt as: MathKernel -noprompt -script file.m On execution, there is a like a kernel window opened and then closed immediately. How can I avoid this window and ...
154 views

### How to add labels to a graph [duplicate]

This should be an easy question but since few examples are given for ShowLegend and I am a new user, I got stuck after many attempts. I plot three graphs which are ...
1k views

### How to neglect higher power terms in a polynomial expression

I have a polynomial expression of order n (say n=20). F(x)=1+x+x^2+x^3++...x^20. I want to approximate the polynomial for order 3 only. So I need to make the ...
172 views

### Manipulate doesn't work for plotting a region where a matrix is positive semi-definite

I'm facing the following problem and would very much like you help. Thanks is advance! I have defined the following 4x4 matrix: S=\left( \begin{array}{cccc} ...
475 views

### random number visualization without generator (Spectral Test) [closed]

Does anyone have codes for using only numbers to make this kind of random-number visualization and not requiring a number generator? ...
416 views

1k views

### Place plot markers in front of error bars with ErrorListPlot

I'm making an ErrorListPlot where the error bars are a different color then the markers and it works, however, the error bars are drawn in front of the markers and ...
312 views

### Making simultaneous equation solving more efficient

I am trying to solve a system of several simultaneous equations that have been generated by a series of modules and functions, using this module: ...
34 views

### Applying Some Kind of Timing Function to AutoRunSequence [duplicate]

Ok, so I'm exporting a video to MOV format that is coming from a manipulate function (I'm demonstrating CLT to a class that doesn't have calculus as a pre-req, if anyone is curious). Anyhow, I'm ...