[問題] int積分,符號轉換成數值的疑問已回收
不好意思想請問一下板上的各位前輩
當我在對function做"int"積分時
有時後會產生出一堆符號組成的結果
例如像:2*pi*3.91e-006之類的
因為要把結果做圖的關係 我必須把它轉換成數值
但是當我用: double(積分出來的結果)
迴圈跑到一定圈數時 都會顯示ERROR! 內容是
Error in MuPAD command: DOUBLE cannot convert the input expression into a
double array.
If the input expression contains a symbolic variable, use the VPA function
instead.
我照他的話作 把double改成vpa
但是當我用semilogy畫圖時 又出現
Error using ==> semilogy
Conversion to double from sym is not possible.
我發現我要畫圖的目標參數竟然裡面有以下的"符號"? "數值"?
(7763572672169889*numeric::int(((erf(u) -
1)*(1/exp((8922155488737387*u)/281474976710656) -
exp(8922155488737387/281474976710656*u)))/exp(2*u^2), u =
0..Inf))/84615164005151820665845159428194693098035799419427996068435045795123941278247852265624218936283556460491675139202989862944768
+ 0.081568353408265299193045100944058, (499338417394573*numeric::int(((erf(u)
- 1)*(1/exp((2808082068187575*u)/70368744177664) -
exp(2808082068187575/70368744177664*u)))/exp(2*u^2), u =
0..Inf))/34808659497239648579720852704622583960672214563358764118798771041101647699040812580153753748454066465596331097210650690541753423472407821641942301328447068696990926165468330002463334596608
- (499338417394573*numeric::int(((erf(t) -
1)*(1/exp((2808082068187575*t)/70368744177664) -
exp(2808082068187575/70368744177664*t)))/exp(3*t^2), t =
0..Inf))/278469275977917188637766821636980671685377716506870112950390168328813181592326500641230029987632531724770648777685205524334027387779262573135538410627576549575927409323746640019706676772864
+ 0.081568353408265299193045100944058
而且我不知道該怎麼轉換它 想請板上各位高手麻煩幫一下忙了
感激不盡~~~~~~
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