Mathematica

Financial Data - Currencies
Does anyone know how to get the names corresponding to the currencies available from FinancialData? If you use the command below you get a list of 153 currencies - some of which are obscure so i was hoping to generate the names! currencyTickers = FinancialData["Currencies"] Also, why does FinancialData not give h... 6 Jan 2010 08:42

More /.{I->-1} craziness
The reason is this: In[1]:= I // FullForm Out[1]//FullForm= Complex[0,1] In[2]:= 1 + I // FullForm Out[2]//FullForm= Complex[1,1] So, "I" is simply a way to write down quickly the expression Complex [0,1], while E and Pi directly represent the numbers E and Pi, without any intermediate transformation. Con... 23 Jan 2010 08:43

Persistent assumption
Hi, Is it possible to make an Assumption for the duration of a block of code? In other words, to say "In all of the following code, Assume[x>0]". I appreciate that it is possible to use, Assuming[x>0, a whole lot of code ] but that's quite awkward. Looking for a better alternative. Thanks, Sam... 31 Dec 2009 03:25

algebraic numbers
x= Sqrt[2] + Sqrt[3] + Sqrt[5] is an algebraic number MinimalPolynomial[Sqrt[2] + Sqrt[3] + Sqrt[5], x] returns the polynomial : 576 - 960 x^2 + 352 x^4 - 40 x^6 + x^8 as expected Now suppose we only know the N first figures of x (N large enough), say : N[x,50] = 5.382332347441762038738308734446846680... 10 Jan 2010 04:15

FindInstance Problem
P.S. I'm apologize but I don't know how to force this condition in Mathematica variable "a" have to be root of polynomial order not higher as 4 That finding Mathematica solution: {Root[93729137781599188892101109375 + 694786929294636041346875*x - 7512992033452287500*x^2 - 667145231722500*x^3 - 2495181500*x^4 + ... 26 Dec 2009 19:51

Taylor expansion of Jacobi's elliptic functions
With Mathematica 7 on Mac OS X Leopard In[1]:= Table[Series[JacobiDN[x, m], {x, 0, n}], {n, 0, 4}]] Out[1]= {SeriesData[x, 0, {EllipticDump`JacobiSum}, 0, 1, 1], SeriesData[ x, 0, {EllipticDump`JacobiSum}, 0, 2, 1], SeriesData[ x, 0, {1, 0, Rational[-1, 2] m}, 0, 3, 1], SeriesData[ x, 0, {1, 0, Rational[-1... 28 Dec 2009 05:17

Replace and ReplaceAll -- simple application
I am doing some manipulations in Mathematica and end up with constructs such as "1." in the expressions. I want to convert these to "1" and thereby eliminate them. However, these examples don't seem to work. This is Mathematica 7 on OS X. In[40]:= Replace[1.(y1-1.yr),1.->1] Out[40]= 1. (y1-1. yr) (* Nothing hap... 14 Jan 2010 06:50

.eps file in MATHEMATICA
I created an .eps plot using MATHEMATICA, and wanna add it into my .pdf file. The plot has a rigion filled using command "RegionPlot" in MATHEMATICA. The picture looks fine in MATHEMATICA and PHOTOSHOP, but when I insert into a .tex file and generate a .pdf file, the filled region shows weird pattern of grids and diago... 26 Dec 2009 19:51

3d Mandelbulb Douady Julia
Resolution isn't much... http://www.flickr.com/photos/fractalmusic/4203226808/ Clear[x, y, z, pc, n] n = 30; norm[x_] := x.x; pc = {-0.122561, 0.744862, 0}; m0 = 3; (* By Roger Bagula and Paul Nylander 21 Dec 2009©*) Square[{x_, y_, z_}] := If[x == y == 0, {-z^2, 0, 0}, Module[{a = 1 - z^2/(x^2 + y^2)}, {(x^2 -... 22 Dec 2009 04:53

Epidemic Model
I wrote a code to show simplified epidemic spreading, but there is a problem, I want to see 100, 150, 200... steps for same epidemics, in this code for every loop, only starting point is same, first, second, third... steps have new values, how can I see 150th steps which starts from 100th step value of same epidemics? ... 20 Dec 2009 07:04