# All Questions

46 views

### How can I round a number up with two decimals? [on hold]

My problem is, that I have to round a number with many decimals to a number with two decimals. For example: The number is 3.467. Now I want to get 3.46. I tried it with Round[3.4647,0.01], but I only ...
58 views

### Problem with Simplify, Sqrt, and Set: What's going on?

I am having some trouble getting Mathematica to simplify an expression of the form Sqrt[x]*Sqrt[1/x], where x>0. The problem is that x is assigned to some complicated form by the time Mathematica ...
73 views

### Plotting Complex Numbers - Functions of Complex Numbers [duplicate]

So I have to generate a few different plots with z, where z is a complete number... z[x_, y_] := x + y*I F[z_] := (25*Pi*z*I)/(1 + 10*Pi*z*I) First, I need to ...
78 views

### How to find and verify relationships between functions?

MMa gave me a complicated result involving Hypergeometric0F1's. It was much less complicated after I discovered this identity: ...
19 views

### Size of the box using Manipulate function

I am using the following command: Manipulate[Graphics[Arrow[{{0, 0}, {a Cos[ω t], a Sin[ω t]}}]], {t, 0, 10, 0.1}] In order to display a vector in circular ...
41 views

### Problem with converting \frac into mathematica output [duplicate]

Please help me with the following problem: TeXForm[2/3] The Answer is correct: "\frac{2}{3}" I don't understand why ...
90 views

### How to find soccer balls in an image? [on hold]

I have 10k images and I need automatically remove only soccer balls, excluding other types (volleyballs, baseballs, etc...). I'd like to use computer vision methods of V10 to find their masks and ...
67 views

### Notebook downloaded from web giving error message

Just bought a copy of E. J. Mcinnerney's textbook Computational Explorations in Magnetron Sputtering. However, when I download and try Chap2.nb from: ...
42 views

### Graphing a vector [duplicate]

I have a vector (in physic) designated asF1=250cos(60)i+250cos(60)j+250cos(45)k, and i would like to see it in a 3D graphic with the axis centered at the origin, after what i would include other ...
41 views

### Increasing CPU usage on Mathematica on a Product [on hold]

I hope someone can help me: I tried Parallelize, ParallelTry and others with AbsoluteTiming, and in every case the time was the same: what I have to do to calculate a Product in mathematica using all ...
38 views

### combining separate data into pairs after reading from excel so I can run regression

I have the following code that reads data from an excel spreadsheet: ...
70 views

### Combining MapAt and MapIndexed

The very last example in the documentation for MapAt is: MapAt applies f repeatedly if a part is mentioned repeatedly: ...
52 views

### How to plot and visualize a single linear vector in 3D? [on hold]

I have a vector (in physic) designated as F1=250cos(60)i+250cos(60)j+250cos(45)k, and i would like to see it in a 3D graphic with the axis centered at the origin, after what i would include other ...
69 views

### Function equal to Ctrl+Shift+I

No, it's not InputForm. Consider this example: ...
44 views

### Usb-harddisk and raspberry

Mathematica on raspberry. External media access. I have a usb harddisk, which is recognized by the system, but apparently not known to Mathematica. The disk is not seen when I try to open files from ...
47 views

### Mysterious message posted when I move the cursor in a custom function

I wrote a function called CPlot for complex plotting which is supposed to act a lot like Plot in its input format, but ever ...
168 views

### Function to calculate average of multiple lists

I have several lists of experimental data f[x] with different intervals Δx including some noise. ...
57 views

### Apply function on 2d array [on hold]

I have a function taking three variables as arguments. I would like to apply it to several random values. So I first created a table of 3 by 10 random values using: ...
54 views

### Why can't I abort main evaluation from ScheduledTasks (Service Link)?

FrontEndExecute[FrontEndToken["EvaluatorAbort"]] is equivalent of the menu item: Evaluation >> Abort. It works with ...
43 views

### How to properly pass function as argument here? --> NMinimize & NIntegrate involved

I had a problem of a similar kind here which was solved. Now after changing a few things in my problem setting I am suffering from the following problem. Let me first introduce methods/functions that ...
60 views

### Dynamic visualization of two histograms

I have two histograms histo1 and histo2: ...
91 views

### Force Mathematica to return numerical answer to (relatively) complicated differential function

I am trying to take the Laplacian of the LogDet of a 2x2 matrix that I call V\[ConjugateTranspose].V, and actually get a number out at the end. Why does Mathematica ...
58 views

### Low CPU usage. How to increase it? Should I?

I'm running a programme, and below are some graphics from the resources monitor from windows 8, while running my programme in version 9 of mathematica. Sorry for the foreign writings in the pics, but ...
35 views

### Find minimum summation and constraint values [on hold]

how can I get mi value to minimize this equation..?
55 views

### Equivalent parametric plots don't look the same

ParametricPlot[ {1, Tan[t]}, {t, -Pi/3, Pi/3}] ParametricPlot[ Sec[t] {Cos[t], Sin[t]}, {t, -Pi/3, Pi/3}] The second parametrization does not plot like the first, ...
51 views

### How to extract data points from an image of a log log plot? [duplicate]

I have a picture of a log-log plot, taken from a paper and I want to extract the data points so I will be able to plot them again along with results of my own solution. I would appreciate your help. ...
37 views

### What is wrong with my following vector plot

I am trying to plot the following: ...
27 views

### Force ReplaceAll to output vector of same length

I would like to do a replace in an expression... a = t; b = 1; a/.t->Range[1,5] (*returns: {1,2,3,4,5} *) b/.t->Range[1,5] (*returns: 1 *) but I ...
400 views

### Something interesting about Pi, but something seems amiss

I saw something interesting about text-analysis - bigrams - in Basic Text Analysis in Mathematica I wondered how the bigrams of Pi's digits might appear. As expected, take enough terms and every ...
38 views

I have: ...
55 views

### How change style of InputField in a Manipulate?

Is it possible to specify a style, e.g., font size, for InputField type controls inside a Manipulate and if so, how? For ...
33 views

### Calling a function on a variable with parameters [duplicate]

I have an equation that contains parameters. I want to use it in a function like NDSolve, but I can't seem to figure out how to do so. Here's an example: I define ...
36 views

### How to separate linear terms by output?

I am performing a complicated summation in which fa is a Sum of a[j] over j, and terms in fa end up containing a BesselJ, a Hypergeometric0F1, or neither. ...
89 views

### How can I overload a function with multiple bracket-slots so f[a][b] and f[a] can coexist?

Maybe this is not even possible: I want to create a function f that can have two input brackets like: f[a_][b_:1]:= a*b and ...
153 views

### How can I construct a recursive pattern guard?

I am modelling binary trees in Wolfram Language by writing them as three-element lists, like so: binTree = {nodeVal, leftChild, rightChild}. It does not yet matter ...
78 views

### How to label my training images?

I'm switching over Matlab, but I have a problem. Matlab has a GUI tool called the "Training Image Labeler" (shown below) that I use all the time to label my training data for my computer vision ...
21 views

### Integers of particular forms [migrated]

For positive integers x,let s(x) be the sum of the digits of x,and let d(x) be the number of digits of x. Is there natural number of the form 10^(8+9n)+8+9n that cannot be written as x+s(x)-d(x) ? (I ...
55 views

### How can one debug a module more elegant than just with Print?

This question is interesting mainly for beginners, but the answer i wrote to my own question could be also interesting for advanced users. Introduction: While writing huge blocks of code, especially ...
54 views

### Can't get solution to a system of recurrence equeations

I would be grateful if someone could help me with this problem. I define two series recursively, thus: ...
42 views

### NestList and RandomChoice from a list of functions

I am tryingg to modify Chaos Game Fractals from Wolfram Demonstrations. The part I am having problem with is this. Original code: ...
108 views

### Isolating cross terms

I have a set of expressions that contains terms like $\frac{1}{(x + a + b)(c+d)}$. I would like to simplify the denominator so that products of $a,b,c,d$ are dropped, but $x c$ and $x d$ are kept. ...
53 views

### How to specify the domain of a variable?

How can I specify for every expression the domain of a variable without using assumptions everytime i have to simplify it?
43 views

### Evaluating documentation example crashes the kernel

Save your work before attempting: Could someone confirm what looks like a bug (definitely occurs in v10 and OSX 10.8.5): In the documentation for Background and ...
40 views

### Linearization of differential equation - need tips for the use of Series function

I would like to linearize a differential equation around a equilibrium position. The description of the steps that I have carried out are : Equation ...
72 views

### Why does FindMinimum return 'The function value Null is not a real number'?

I am working with the following function ...
20 views

### Fit a complicated function to a constant with NonlinearModelFit

I wish to fit a complicated parametric function (logder, with lambda parameters) to a constant (L) in order to minimize its dependence with the variable k in a given interval. To do that, I use a ...
20 views

### Using Coefficient to pick combinations of parameters in an expression

I have the expression  c \partial_{\chi} u = \mu u - \nu v - (u + \beta v)|A|^2 + (\partial_{\chi}^2 u - \alpha \partial_{\chi}^2 v) + \gamma u \\ c \partial_{\chi} v = \mu v + \nu u - (v - \beta ...
66 views

### Overlay vector logarithmic plot and rasterized logarithmic ListPlot

I would like to produce a output PDF file of a log-linear plot obtain by composing the plot of an analytical function and a scatter plot of some random data. Since the random points are of the order ...