0
votes
0answers
7 views

Getting rid of functions that cancel themselves out

So when I perform calculations on lengthy expressions, I end out with results littered with √(expr^2). In fact, even if I use Simplify[√(expr^2)], it doesn't reduce to expr. Why? I sorta have it in ...
3
votes
0answers
40 views

Exported CDF file does not include GeoGraphics

I'm trying to display a map on manipulate and the case is .nb files shows it but when I export it to .cdf this format not show the GeoGraphics map ...
1
vote
1answer
7 views

Control Word Wrap in Grid cell

I'm trying to display a number tables of data in my document which have column headings that are longer than the cell width for those columns so they need to wrap within the grid cell. I have no ...
9
votes
2answers
392 views

How to add a vertical line to a matrix?

Today, I want to write a program to show the solving process of a the inverse of a matrix, and I use the Elementary Transformation, so I need to add a vertical ...
6
votes
1answer
133 views

Easy FindMaximum returns a wrong answer

FindMaximum in region is a new function in mma10,but when I tried the following example: ...
0
votes
0answers
6 views
11
votes
1answer
53 views

Change in Lighting and Show in V10?

According the documentation for Show: Options explicitly specified in Show override those included in the graphics ...
4
votes
1answer
198 views

Exporting multiple arrays in a single HDF5 file in Mathematica 7

Bug introduced in 7.0 and fixed in 8.0 I am using Mathematica 7 and I need to export a table of data and the corresponding x and ...
5
votes
2answers
78 views

How can I change the thickness of tick marks in BarLegend?

This answer explains how to change various undocumented options for BarLegend with Method. In particular, I want to change the ...
3
votes
0answers
118 views

An recurrence equation that can be solved in version 7 but not in version 8

Backslide introduced in 8.0, fixed at least in 9.0.1. A friend of mine showed me this code sample: ...
0
votes
0answers
15 views

Plot given points\lines\arcs in 3D

I need to plot 6 points in 3D. I used the command 'Plot' but I couldn't draw it. The coordinates of points $A,A,B,B',C,C',D$ are given. $AD,BD,CD$ are straight line segments $AA',BB',CC'$ are arcs ...
1
vote
0answers
58 views

PDE: solving Fokker-Planck equation with initial and boundary condition [migrated]

Here is the problem. We have the following simple PDE: \begin{equation} \frac{\partial p(x,t)}{\partial t}= - a\frac{\partial p(x,t)}{\partial x} + \frac{D}{2} \frac{ \partial^2 p(x,t) }{\partial ...
1
vote
0answers
27 views

Why can't I paste data from Notepad into Mathematica 10 in Windows 8.1?

I can't paste data that I have copied from Notepad in Windows 8.1 into Mathematica 10. I was able to do this when I had Windows 7 and Mathematica 8. Now when I try to paste into Mathematica 10 using ...
8
votes
3answers
143 views

Part of an Image cut/lost when exported to EPS file

When making .EPS image files for publication, I tried to assemble several Graphics by Grid. For example, suppose I have: ...
3
votes
1answer
35 views

Module inside of Manipulate Example

Here is a very nice example from The Student's Introduction to MATHEMATICA. ...
15
votes
0answers
209 views

RegionPlot returning a number

Bug introduced in 10.0 and persisting through 10.2 or later I had updated my mathematica to version 10 few days ago. And I had been shocked by the following fact: ...
27
votes
0answers
522 views

Version 10 cannot print properly?

Bug introduced in 10.0 and persisting through 10.2 or later I have two problems with printing in version 10. First, I can't print correctly with a setting of printing scale For example, I have ...
3
votes
1answer
52 views

How to define UpValues about the derivative of NBSpline when the length of knots is unknown?

Description In the book “Programming in Mathematica” 3rd by Roman.E.Mader, the author gives a topic about A new Mathematical Function in section 8.4. For instance, for the following formula: ...
0
votes
0answers
22 views

Why does my contour plot have missing blotches? [on hold]

I think it may have to do with areas on the plot that are very small in value.
6
votes
0answers
24 views

Incorrect Display on Linux (+HiDPI)

I have Linux on a HiDPI laptop, and after first installing Mathematica, the default font size is far too small: After searching for a few solutions, this can be fixed by either changing the ...
3
votes
0answers
96 views

Det and MatrixRank freezes on SparseArray with nonzero default value

Bug introduced in 7.0 or earlier and fixed in 9.0.1 or earlier Why does the following simple code never come to an end (at least with version 8) ...
1
vote
1answer
64 views

Find an instance satisfying an inequality involving sums

Good day. I am new to Mathematica and I am looking for advice. Is it possible to solve $$\sum_{k=0}^{n} \frac{p^k}{k!}>0$$ for $n$ where $p$ is a constant parameter? When I do ...
8
votes
4answers
321 views

Unexpected behavior from GatherBy in version 7

Bug introduced in 7.0 or earlier and fixed in 8.0.4 or earlier I have come across what appears to be a bug in GatherBy. It appears similar to the problem of ...
7
votes
0answers
207 views

Mathematica 7: “LessEqual::nord:” error when using NMinimize on a real function

Bug introduced in 7.0 or earlier and fixed in 9.0 I encounter a problem (Mathematica 7) similar to Strategies to avoid LessEqual::nord in NMinimize? but the advised strategies don't work for me. ...
8
votes
2answers
637 views

Problem with ContourPlot3D

Bug introduced in 7.0 and fixed in 9.0.1 The following line works fine: ...
7
votes
3answers
561 views

Plotting a 3D list causes kernel to crash if x and y axes have vastly different scales

Bug introduced in 7.0.1 or earlier and fixed in 10.0.2 or earlier I have access to two versions of Mathematica, version 7.0.1 on Linux and version 8 on Windows. When I try the following two lines ...
4
votes
1answer
34 views

Problem Using Evaluated Replace with Associations

If I define some function like: toISOdate[data_List]:=DateString[data,{"Year","-","Month","-","Day"}] and try to applicate it in an ...
2
votes
0answers
392 views

Simple contour integral with a parameter gone wrong

Bug introduced in 7.0 and fixed in 7.0.1 I run into the following problem, I tried to evaluate a very simple integral: ...
6
votes
0answers
270 views

NullSpace[_, Method->“OneStepRowReduction”] is sometimes wrong; how can I work out when this happens?

Edit 2015: Has this been fixed yet? (This is on MMA 7.0.1.0 on OS X) I've just found a large matrix m for which NullSpace[m] ...
9
votes
2answers
205 views

Held keys in associations

Jacob Akkerboom commented: Note that PositionIndex does work correctly with held expressions, whereas this is a bit painful to implement using ...
3
votes
2answers
47 views

How can I adjust the global input variable of a function to the value of a local variable within the function

I am trying to define a function f[l_] that will perform an operation on whatever input variable I use (normally I use l which ...
12
votes
9answers
485 views

Generating a matrix using sublists A and B n times

I want to write a function that generates a square matrix from sublists. My sublists are a = Range[0, x, 0.5]; b = Range[0.25, x + 0.25, 0.5]; Suppose x=2, then I ...
3
votes
1answer
32 views

Change Property without re-evaluating [duplicate]

I am working with ContourPlot3D, and my expression takes a long time to evaluate (nearly 20 minutes). So I am wondering if there is a method to changing format ...
1
vote
0answers
38 views

Reducing quantile & color map queries for use with Associations

This set of queries perform basic maps to quantile and then color-map. There's got to be a more compact solution. What are some approaches to reduction? Numeric: ...
1
vote
1answer
119 views

Appending elements to a list in parallel table

Is there any way to store values in a list that is being computed in parallel? For example, if ParallelTable is computing some ...
5
votes
3answers
146 views

How to imitate list comprehensions for constant arrays?

In Python, ['a'] * 10 generates ['a', 'a', 'a', 'a', 'a', 'a', 'a', 'a', 'a', 'a'] and ...
0
votes
0answers
61 views

Why does this Graphics3D example change lighting on reorient?

What I do: Graphics3D[{Sphere[]},Lighting -> "Neutral"] What I get: but when I reorient: What I want: a stable result! PS The Platform is Wolfram ...
-4
votes
0answers
31 views

If a given # is 70% of X. How do you determine what X is? [on hold]

given I have the number 50,000 which is 70% of X. How do I calculate what X is without guessing. Thanks
3
votes
3answers
163 views

Inefficient NIntegrate and Which

In version 10 a simple numerical integraton of piecewise function is highly inefficient: ...
3
votes
0answers
21 views

DynamicModule's Deinitialization & CDFDeploy

This evaluates fine for me: CDFDeploy["test.cdf", DynamicModule[{}, Dynamic["Hello World"], Deinitialization :> 1]] But this results in a never ending ...
1
vote
2answers
214 views

Problems finding intersection points between line and generic function

I'm trying to find Intersection points between a line, which is given by 2 points, and a generic function (I want it to be able to handle polynomial functions, circles/ovals, lines and all ...
0
votes
0answers
30 views

How to change number form of Plot Legend in ListContourPlot?

I am creating a ListContourPlot from some very large values. I would like these numbers to be written out in scientific notation (8x10^8, etc.) I've tried the following code: ...
1
vote
2answers
78 views

How to write a loop

I try to create a table which will describe traffic paths at a crossroads. Instead of using copy-paste repeatedly, I would like to write a loop. For example: ...
1
vote
0answers
40 views

How to produce timely spoken text?

On my system (Mac OSX 10.10.4) the following code produces only the first utterance. The second one is produce when the user interacts in some way with the front end (mouseover, mouseclick). How can I ...
18
votes
1answer
175 views

Systemic bugs in GraphPlot and related functions such as TreePlot and TreeForm

Bug introduced in 7.0.1 or earlier and persisting through 10.2.0 I believe I have come across a rather curious bug in TreeForm: ...
0
votes
0answers
8 views

Don't understand about how to solve the first equation with Gauss Elimination [migrated]

Please take a look at the picture. My quesion is: How to solve the first equation with Gauss Elimination that is displayed in the picture. I don't understand HOW.

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