Mathematica Mathetica function (help fix my equation please)

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The discussion revolves around troubleshooting issues with Mathematica equations and converting them into LaTeX format. The user initially encounters errors when trying to compute specific values for a recursive equation, particularly with the summation syntax. Key problems include incorrect iterator usage and localization of variables, leading to errors like "Raw object cannot be used as an iterator." After receiving guidance, the user successfully resolves the issues with the summation format by changing the iterator from "z" to "i." Additionally, there is a request for assistance on how to represent absolute values and real numbers in LaTeX for better presentation in physics forums. The conversation emphasizes the importance of clear code formatting for troubleshooting, with a preference for using plain code over fancy formatting to simplify error identification.
Shawj02
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Hi guys,

I have a problem with Mathematica. The equation (see attachment) is SUPPOSE TO give:
n[0]=n0
n[1]=x0-n0
n[2]=x1-x0+n0
n[3]=x2-x1+x0-n0
n[4]=x3-x2+x1-x0+n0
n[5]=x4-x3+x2-x1+x0-n0
n[6]=x5-x4+x3-x2+x1-x0+n0-1
...

But when I put in n[1] I get the following errors and output:

Sum::itraw: Raw object 1 cannot be used as an iterator. >>
Sum::vloc: The variable 1 cannot be localized so that it can be assigned to numerical values. >>
Sum::itraw: Raw object 1 cannot be used as an iterator. >>
Sum::vloc: The variable 1 cannot be localized so that it can be assigned to numerical values. >>
\sum _{1=1}^1 (-1)^{1-1} x_{1-1}-n_0

What do I need to change to give me an output of x_ 0 + n_ 0n[2] gives:
\sum _{2=1}^2 (-1)^2 x_{2-1}+n_0
when I want it to give me: x_1-x_0-n_0
 

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jedishrfu said:
You might try TexForm to do a conversion to Latex:

http://reference.wolfram.com/language/ref/TeXForm.html

I been playing around with the LATEX thing.. using Mathematica's right click and "copy as Latex" function.
I have attached a copy of my original equation, below is an attempt to convert it into Latex.

\sum _{z=1}^z (-1)^z x_{z-1}-\sum _{z=6}^z 1+n_0 (-1)^z

There seems to be a problem with "Reals" and "Absolutes" How do I do these in Latex?
 

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The problem is your summation.
Shawj02 said:
\sum _{z=1}^z (-1)^z x_{z-1}-\sum _{z=6}^z 1+n_0 (-1)^z
\sum _{z=1}^z f(z) is bad input. It should be something like
\sum _{i=1}^z f(i)
 
Dale said:
The problem is your summation.
\sum _{z=1}^z f(z) is bad input. It should be something like
\sum _{i=1}^z f(i)

Yep, you're right! I've got it working perfectly now!

My other question is: How do I write the ABS and REALS in LATEX? (so I can post things on physics forms better)

so far I've got:

\sum _{j=1}^z (-1)^j x_{j-1}-\sum _{j=6}^z 1+n_0 (-1)^z
 

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Shawj02 said:
My other question is: How do I write the ABS and REALS in LATEX? (so I can post things on physics forms better)
When I am trying to troubleshoot I would rather just have the straight code. The fancy formatting is nice, but makes finding code errors more difficult. I know that isn't everyone's preference, but it is my preference. I would just use the "code" tag and copy and paste the Mathematica input.
 

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