simplify
in [Matlab]
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From: Wesley Ooms on 27 Jul 2010 08:28 Dear people, the expression m1*(-sin(q0)*(-cos(q2)*d1-cos(q6)*d4)+cos(q0)*sin(q1)*(sin(q2)*d1+sin(q6)*d4))^2+m1*(cos(q0)*(-cos(q2)*d1-cos(q6)*d4)+sin(q0)*sin(q1)*(sin(q2)*d1+sin(q6)*d4))^2 can be simplified to (-cos(q2)*d1-cos(q6)*d4)^2+sin(q1)^2*(sin(q2)*d1+sin(q6)*d4)^2; (m1, q0,q1,q2... are all symbolic variables) However, the simple, or horner, or collect or simplify or factor routine cannot find the simpler expression. I have almost a dozen of these expressions (121 to be exact). I found matlab could not simplify the expression, so i simplified them all manually. But I'd like to use a matlab routine since that is more reliable, and can be upscaled. the problem seems to be that matlab doesn't see sin(q0)^2+cos(q0)^2=1. Also, in the collect routine, I can force matlab to collect for example sin(q0)^2, but not sin(q0)^2+cos(q0)^2, and it doesn't seem to work either. can anyone please help me Thanks very much, Wesley
From: Walter Roberson on 27 Jul 2010 10:37 Wesley Ooms wrote: > Dear people, > > the expression > > m1*(-sin(q0)*(-cos(q2)*d1-cos(q6)*d4)+cos(q0)*sin(q1)*(sin(q2)*d1+sin(q6)*d4))^2+m1*(cos(q0)*(-cos(q2)*d1-cos(q6)*d4)+sin(q0)*sin(q1)*(sin(q2)*d1+sin(q6)*d4))^2 > > > can be simplified to > > (-cos(q2)*d1-cos(q6)*d4)^2+sin(q1)^2*(sin(q2)*d1+sin(q6)*d4)^2; Please recheck your result. Your simplified expression does not contain m1.
From: Wesley Ooms on 27 Jul 2010 12:06 Walter Roberson <roberson(a)hushmail.com> wrote in message <jaC3o.2186$F%7.1107(a)newsfe10.iad>... > Wesley Ooms wrote: > > Dear people, > > > > the expression > > > > m1*(-sin(q0)*(-cos(q2)*d1-cos(q6)*d4)+cos(q0)*sin(q1)*(sin(q2)*d1+sin(q6)*d4))^2+m1*(cos(q0)*(-cos(q2)*d1-cos(q6)*d4)+sin(q0)*sin(q1)*(sin(q2)*d1+sin(q6)*d4))^2 > > > > > > can be simplified to > > > > (-cos(q2)*d1-cos(q6)*d4)^2+sin(q1)^2*(sin(q2)*d1+sin(q6)*d4)^2; > > Please recheck your result. Your simplified expression does not contain m1. Oh, I'm sorry. I forgot to premultiply with m1, so I ment that it can be simplified to m1*((-cos(q2)*d1-cos(q6)*d4)^2+sin(q1)^2*(sin(q2)*d1+sin(q6)*d4)^2). but matlab still won't find the simplified version
From: Walter Roberson on 27 Jul 2010 12:11 Wesley Ooms wrote: > Walter Roberson <roberson(a)hushmail.com> wrote in message > <jaC3o.2186$F%7.1107(a)newsfe10.iad>... >> Wesley Ooms wrote: >> > Dear people, >> > > the expression >> > > >> m1*(-sin(q0)*(-cos(q2)*d1-cos(q6)*d4)+cos(q0)*sin(q1)*(sin(q2)*d1+sin(q6)*d4))^2+m1*(cos(q0)*(-cos(q2)*d1-cos(q6)*d4)+sin(q0)*sin(q1)*(sin(q2)*d1+sin(q6)*d4))^2 >> > > > can be simplified to >> > > (-cos(q2)*d1-cos(q6)*d4)^2+sin(q1)^2*(sin(q2)*d1+sin(q6)*d4)^2; >> >> Please recheck your result. Your simplified expression does not >> contain m1. > > Oh, I'm sorry. I forgot to premultiply with m1, so I ment that it can be > simplified to > m1*((-cos(q2)*d1-cos(q6)*d4)^2+sin(q1)^2*(sin(q2)*d1+sin(q6)*d4)^2). > but matlab still won't find the simplified version Maple 13 has trouble finding the simplification as well. I do not have my copy of Maple 14 installed anywhere so I cannot test with that.
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