Math Forum / Math Software / Mathematica / July 2009

I have faced a awkward situation in Mathematica. I want to sum the following
simple equations:
DTEP12 = 0.11 (80000 - 12000 P + 800000 (1 - R)) +   0.11 (40000 - 12000 P +
1000000 (1 - R)) + 0.28 (-12000 P + 1200000 (1 - R))

Dear Community,
This question seems to be an important one, if to judge by the number of comments.
I would like to look at this problem from a little bit different perspective.
I belong to the group #3 according to AES classification cited below. And as such, I see great

You might enjoy looking at some Mathematica animations created by a
group of 30 very bright high school students at the Vermont Governor's
Institute in Mathematical Sciences about a month ago. (I meant to post
the link here sooner, but am just now getting around to it.)

I've attempted to convert a Decimal BASIC 7 program to Mathematica 7,
but can't get the graphics to work as expected. Can anyone help? The
source and my conversion code follows:
<--- Decimal BASIC source --->

Hello, everyone.
I'm having a problem integrating to find an arc length.
I have two parametric equations:
x=e^(2t)

If this isn't a bug, sure seems like it should be!
  In[247]:= Do[y=2; y=3, {1}]
  In[248]:= %
  Out[248]= 3

I was trying to modify a list by adding 1 to a certain element.
I can't understand the following result:
h[x_List, a_Integer] := ReplacePart[x, a -> x[[a]] + 1]
h[{1, 2, 3}, 2] gives {,3,3} (what happened to the first element?) but

i import a bitmap with 500x500 points with:
Import["filename.bmp","Data"]
With ArrayPlot i can take a look at the image:
ArrayPlot[%]

Sorry, but I don't. Mathematica for me is just a tool among other similar
tools. It's an environment for technical computing with another arbitrary

I am trying to compose a Mathematica notebook to implement the Prony
method as described by Siegman and Miller ("Unstable Optical Resonator
Loss Calculations Using the Prony Method." Applied Optics 9:2729-2736
(1970)).

Can be changed meaning of input <space> for infix
NonCommutativeMultiply instead of infix Times?

I have following piece of code:
--------------------------------------------------------------------------------------------------------
In[1]:=BifurcationDiagram[f_, {r_, rmin_, rmax_, rstep_}, {x_, x0_},
start_,

When one uses Interpolation[], one gets in return an InterpolatingFunction object which typically formats in the front end as something like
InterpolatingFunction[{{0.,1.}},<>]
How does it achieve the "<>" standing for all the massive amounts of internal data? I'd like to do ...

Hello, everyone.
I would like to group the graph like the command "subplot" in another system, but I didn't notice any similar function to implement it.
For example,
Plot[{Sin[x]}, {x, 0, 2 Pi}]

In[75]:=
b[3, 5, 7][[1]]
Out[75]= 3
In[77]:= Sequence[3, 5][[1]]