Re: Total Derivative and Output Display Question
- To: mathgroup at smc.vnet.net
- Subject: [mg65127] Re: Total Derivative and Output Display Question
- From: "Matt" <anonmous69 at netscape.net>
- Date: Wed, 15 Mar 2006 06:28:55 -0500 (EST)
- References: <duubsl$h0s$1@smc.vnet.net><dv69pb$ocs$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi Daniel, Thanks for your response. First off, let me clarify that I am not knocking Mathematica, rather, whenever I find it difficult or impossible to do something in Mathematica, I usually assume it is due to my ignorance of the system, which is what I meant when I said that my approach was burdensome and convoluted. Now, onto the question at hand. The way in which you mapped the Mathematica output to the traditional output with Derivative[0, 1][z][x[r[t], s[t]], y[r[t], s[t]]] to be dz/dy Derivative[1][s][t]*Derivative[0, 1][y][r[t], s[t]] to be dy/ds ds/dt Derivative[1][r][t]*Derivative[1, 0][y][r[t], s[t]] to be dy/dr dr/dt Derivative[1][s][t]*Derivative[0, 1][x][r[t], s[t]] to be dx/ds ds/dt Derivative[1][r][t]*Derivative[1, 0][x][r[t], s[t]] to be dx/dr dr/dt Derivative[1, 0][z][x[r[t], s[t]], y[r[t], s[t]]] to be dz/dx is more or less exactly how I set up my replacement rules. But even after doing that, I still didn't get the output required, because Mathematica rearranged the order of the derivatives, making the output non-sensical (which, I admit, could be due to my applying the rules incorrectly). I know that I could go through some elaborate machinations using HoldForm and finding the various parts I want to rearrange (I think), but again, that seems to be a horrible solution to a problem that should be so simple. Mathematica is used for many things, but actually doing mathematics is, I believe its raison d'etre. Granted, from what I read in the documentation, Mathematica's solution is very general and elegant, it is, nonetheless gibberish to any mathematician not familiar with the peculiarities of Mathematica syntax. I am just surprised that there isn't a simple and elegant way to get output that would be readable by a person not familiar with Mathematica. For instance, a person trying to do their Calculus homework would have spent much more time trying to contort Mathematica's output into a form readable by the teacher, than they would have by just working it out on paper and turning it in. Matt