Re: Problem trying to Solve for 'theta' ... v6.01
- To: mathgroup at smc.vnet.net
- Subject: [mg84804] Re: Problem trying to Solve for 'theta' ... v6.01
- From: Bill Rowe <readnewsciv at sbcglobal.net>
- Date: Tue, 15 Jan 2008 03:15:22 -0500 (EST)
On 1/14/08 at 6:50 AM, lrebanks at netvigator.com (Lea Rebanks) wrote: >I am having a problem trying to solve for 'theta' & cannot find the >appropriate function / method to do this. I am using Mathematica >version 6.01 on a PC. Any advice gratefully received. >PS - pasted coding below. >Solve[2 (-1+IntegerPart[1+q/360]) >IntegerPart[1+q/360]+IntegerPart[1+q/360] >Mod[IntegerPart[q/90],4]+1/Csc[=B0 (135-Mod[q,90])] >IntegerPart[1+q/360] Sin[=B0 Mod[q,90]]*Value,q] Several comments. First, it is greatly preferred that you first convert code to input form before pasting into email. That way, anyone trying to review your code can easily paste it into Mathematica. If you do not first convert to input form, things that do not have a simple ASCII form get changed into something not readily recognizable. Next, Value is a reserved system symbol as can be seen by executing ?Value in a fresh session. You should not be using this as a variable name. In general, it is good practice to use lower case letters for the start of you variable names since this is guaranteed to prevent conflicts of this nature. Look at the documentation and syntax for Solve. You need to provide as arguments an equation and a list of variables. You have not done so. The first argument you have provided is an expression, not an equation. And your second argument asks only for the solution for q not theta. Finally, Solve is primarily intended to solve polynomial equations. It will generally work for simple non-polynomial equations usually generating a warning about using inverse functions. Assuming what you meant to do is have the expression you provided above equal some constant, the resulting equation is clearly non-polynomial in the variables and does not look like one of the simple cases Solve will be able to handle. I am guessing you want a numerical rather than symbolic solution. If so, look at using NMaximize, NMimimize or FindRoot here instead of Solve. -- To reply via email subtract one hundred and four