8
votes
4answers
3k views

Can one force a linear regression fit to go through the origin?

As the question says, can one force a fit through the origin $(0,0)$ as one can when fitting a trendline to your data in MS Excel? If so, how do you do that?
3
votes
1answer
191 views

How can I find the average of the ordinate of an indefinite number of lists of points?

Suppose that I have three lists: list1 = {{0, 1}, {0.1, 10}, {0.2, 100}}; list2 = {{0, 1}, {0.1, 10}, {0.2, 100}}; list3 = {{0, 2}, {0.1, 20}, {0.2, 200}}; In ...
11
votes
4answers
737 views

Ordering vertices in GraphPlot

I'm new here, so forgive me if this question is not well-posed/duplicates an earlier question - although I've searched for similar questions without success. I'm trying to present a plot of ...
4
votes
2answers
2k views

Set default font for Output

Is it possible to set the font family to Arial for axes, legends and labels globally? I found out about ...
6
votes
2answers
216 views

DateList Segmentation of data

I've been trying to separate large segments of DateList formatted data (years worth at a time) into individual days using the Split function. The data has the form: ...
17
votes
5answers
5k views

Plotting discontinuous functions without spurious vertical segments

Consider the plot of this discontinuous function: f[x_] := If[2 < x < 3, 0, x] Plot[f[x], {x, 0, 5}] I'd like to plot that without the vertical segments. ...
4
votes
3answers
422 views

How could I get the value of y[t] at each specific interpolation point?

sol = NDSolve[{Derivative[2][y][t] + Sin[y[t]] == 0, Derivative[1][y][0] == 0, y[0] == 1}, y, {t, 0, 2}] the above-mentioned differential equations can be solved ...
0
votes
1answer
322 views

Iterative way to find roots of confluent hypergeometric function

I am trying to find roots of confluent hypergeometric function and I wonder if I can choose the initial guess by the choice of $\beta$. ...
28
votes
4answers
2k views

Clustering of space-time data

Below is an example of a gaze sequence I recorded during a 3 seconds display. That is, where the eye was at every millisecond. While we should have 3000 points, we are missing some due to blinking. ...
1
vote
1answer
168 views

Computing a logarithmic function

Possibly this is a very lame question for this site. There is a function $f(n)=-\ln(a*n); \space \Bbb Z \to \Bbb R$, and I want to define $a$ for pairs of values. For example: $f_1(n_1)=15; ...
4
votes
4answers
665 views

How to define and use a linear function

I have the following equation $T = -800n + 12000$. I know that this is a linear function and that the two points $(0, 12000)$ and $(15,0)$ lie on the line. When I have 2 other values of n between 0 ...
6
votes
2answers
683 views

Trying to extract information from an MDB file. Import is too slow

I am running a Linux box and as usual the documentation for this type of box is not great. I am trying to open up and extract and possibly include later on information from a "mdb" file. The file ...
3
votes
0answers
218 views

Changing scroll rate for page down key?

I have a presentation remote that allows me to advance Mathematica slides when in the SlideShow environment. The control sends a page down key. Some of my slides extend below the screen window, and ...
3
votes
3answers
591 views

How can I change the CDF which imports the data and uses it, without execution of code

I am making an application which first imports the data from the Excel file and then uses it in the deployment of a CDF. But is it possible to change the data of the Excel file and see its ...
3
votes
2answers
761 views

Is there a way to get user input when running a script on a Linux terminal?

I have access to a node of a Linux cluster, on which Mathematica is installed. However, I do not have access to a Linux GUI. Typically I write and test Mathematica scripts on my Windows personal ...
1
vote
1answer
544 views

Using previous two solutions as a start point in FindRoot

I need to solve a sequence of equations and I want the starting point of each new FindRoot to be the solution of the earlier FindRoot, increased or decreased by a a bit in the following way: Some ...
4
votes
2answers
5k views

How do I plot $x^2+y^2=1$ in 3D?

How would I plot $x^2+y^2=1$ in 3D (it would form a cylinder)? Since there is no $z$ in the equation, I can't solve for it and use Plot3D. Or can I just put the ...
6
votes
2answers
380 views

3D Plot: Number of Roots in x of a polynomial in x, a, b and c

I have a polynomial in four variables x,a,b and c. The number of roots of the polynomial in x depends of the choice of a, b and c. I would like to have a 3D-Plot with a, b and c on the axes, while the ...
4
votes
4answers
3k views

How to convert equation to vector (matrix) form?

How can I convert expression a1*u1+a2*u2+a3*u3 to the vector form of dot product A.U, where ...
7
votes
1answer
290 views

How to make InputTable

There is InputField in mma but how to make InputTable? In MathCAD it`s possible to insert Excel spreadsheet with input and output variables.Input variables I use for filling of header row and column ...
5
votes
6answers
402 views

How to change specific values in a List [duplicate]

In a list lst I want to change all values > 255 to 255. Why is this code not working? ...
3
votes
2answers
286 views

Find all points that have the same minimum? [duplicate]

Possible Duplicate: How to find all the local minima/maxima in a range Sin[x] have two points ($3\pi/2,7\pi/2$) where the same minimum ($-1$) is achieved ...
10
votes
8answers
2k views

Map and Apply a function on a nested list

I have a list like this: {{1,2}, {4,2}, {6,4} ... } I want to replace every second number with a function of that number. For e.g. ...
8
votes
0answers
255 views

Using Compile to speed up Function with PermutationProduct

I have the following fairly simple routine dot involving PermutationProduct that I wish to speed up using ...
10
votes
2answers
4k views

Equation of a line that is tangent to a curve at point

A common problem in the derivative section of calculus texts is "find the equation of the line that is tangent to the curve $y = \ldots$ at the point $P$." To find the line that is tangent to $y = 2 ...
2
votes
1answer
184 views

Controlling CDF window size

I want to ask how can I control the CDF WindowSize in such a way that the end user can minimise its size upto some extent only. ...
8
votes
2answers
410 views

Series expansion with irrational power

I need the series expansion of a fairly nasty function and its derivative: ...
2
votes
4answers
2k views

How to export data from For loop in text file?

I'm new in Mathematica and I am trying to write numbers from 1 to 10 in txt file. But "Null" is everything that is written in my file. The code is: ...
3
votes
2answers
426 views

Representation of negative exponents [duplicate]

Possible Duplicate: Way to improve “show me this decimal number to M places, don't use scientific notation”? How can I expand e.g. number 1.*10^-8 so that there would be no ...
4
votes
3answers
198 views

Is it possible to replicate the “magic” of OptionPatterns[] with DynamicModule's local variables?

Creating richer interactive interfaces that are generated by a DynamicModule invariably requires more complex data structures and in particular, a larger argument ...
19
votes
2answers
1k views

Efficient way of finding shortest distance between two sets of points in mathematica

I have two sets of 3D points, say a = RandomReal[1, {10, 3}]; b = RandomReal[1, {10, 3}]; I wanna find the first N pairs that have shortest distance between the ...
8
votes
2answers
481 views

Generating a position lookup function for an arbitrary list of integers

In my code, I generate a list of integers called numlist. Here is an example numlist: ...
1
vote
1answer
246 views

Not able to load the package in CDF

I am facing a problem in loading the package. My code is working in Mathematica but after deploying it into CDF, it is unable to ...
1
vote
2answers
399 views

Piecewise function with a function as argument

I want to define a piecewise function, which has two arguments, one of which is a function of the other's piecewise argument. I am giving an example ...
2
votes
1answer
81 views

`Trigger` autorunning when not supposed to

Recently I was trying to make something where one could vary the parameters and press play to see how the animation changed. However, when I tried running the code it would just start automatically. ...
8
votes
1answer
307 views

Confused by (apparent) inconsistent precision

$$ e^{\pi \sqrt{163}} \approx 262537412640768743.99999999999925 $$ E^(Pi Sqrt[163.0]) N[E^(Pi Sqrt[163.0]), 35] NumberForm[E^(Pi Sqrt[163.]), 35] returns ...
3
votes
1answer
560 views

Selecting polynomial roots and plotting against parameters

An implicit function $f(x,k)=0$ is quadratic in $x$ and contains one parameter $k$ which I must vary. Using Solve, I get two real solutions for each specific $k$: ...
5
votes
1answer
187 views

Simulating CoordinatesToolOptions (for CDF) & the Inflexibility of MousePosition

I got two lists of equal lengths, which I show in two ListPlots, arranged in a Column or ...
1
vote
0answers
186 views

How to move differentation before the integral?

I have quite a lot expressions that need to be integrated after switching the integral sign with differentation operator. The additional problem is that the bounds are dependent to one of the ...
1
vote
2answers
152 views

How can define a set of nested parameters

I would like to know how I to define a function with a nested set of parameters (or whatever you would like to call it). For example, how would I get the following function ...
2
votes
1answer
120 views

How to prevent substitution?

I have a function: $\bar{u}:=u[t,x,y,z]$ (1) How do I prevent it from expanding and substituting in instructions like those following: $\partial _t {\bar u}$ (2) Thanks in advance EDIT: ...
11
votes
5answers
700 views

How to plot rectangles aligned by their center?

Supose I have a rectangle which area is $x^2$. In some cases I may not know what is the size of each side, for $x=12,$ we have several possibilites: ...
10
votes
2answers
3k views

How to get Matlab data imported with the same dimensions?

I have some Matlab image data with the following dimensions (output is from Matlab): >> size(im) ans = 86 86 3 45 The data imports just fine ...
4
votes
1answer
271 views

Upon opening my notebook, I must evaluate cell for code to work properly

I am new to Mathematica. Once I evaluate the cell containing the code, my Manipulate works as desired; however, if I open the file and do not evaluate the cell, the Manipulate goes haywire. Can ...
11
votes
0answers
163 views

Is there a convenient/automatic way of uploading a notebook into SE?

This post discusses how to streamline the other way - extracting code from a fragmented and longish SE answer but I imagine a two-way workflow like: Fashion an answer/question in an SE-templated ...
4
votes
2answers
569 views

Clustering a bivariate data set with Mathematica

I need to partition a bivariate data set into predetermined "n" clusters and, at the same time, to fix the centroid position of each cluster. Is the ...
2
votes
2answers
274 views

How to output an expression as a Dot[] product

How to force Mathematica to output an expression such as $a1u1+a2u2+a3u3$ as a Dot product like this one: ...
3
votes
1answer
445 views

Problem in RegionPlot3D

I tried to plot the region bounded by the three planes. This is supposed to give me a pyramid type of shape (actually two, but I am just taking one of them). The code is given by ...
6
votes
1answer
481 views

Count sublists which match pattern

I have a list which looks like this: data={{12,0},{0,0},{20,1},{0,0}, {0,-1}}. Now I would like to count the number of sublists which: have both slots zero the ...

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