How do I get the exact x value that find-root used

asked 2020-10-22 03:17:45 +0200

cybervigilante
401 ●8 ●26 ●38

updated 2020-10-22 03:27:15 +0200

I was using this simple algorithm to find roots, but it occurred to me that I want the exact x-value at the point where find_root locates the yval. Except I'm only using the last xval. I'm unclear how I could get the actual xval that find_root used when finding the zero.

roots=[]
for xval in [-10..5,step=.1]:
    try:
        yval=find_root(cos(x)-exp(x),xval,xval+.1)
        roots.append((xval,0))
    except:
        pass

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answered 2020-10-22 17:04:00 +0200

Emmanuel Charpentier
7057 ●6 ●46 ●137

The answer(s) of interest is(are) the yval values, the xval values are the bounds of the search interval. If those are the bounds you are interested in, you may try :

roots=[]
for xval in [-10..5, step=.1]:
    try;
        yval = find_root(cos(x)-exp(x), xval, xval+.1
        root.append((xva, yval, xval+.1))
    except:
        pass

which gives you a list of solution bracketed by the search bounds leading to them, but I have trouble seeing the point...

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Asked: 2020-10-22 03:17:45 +0200

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Last updated: Oct 22 '20

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How do I get the exact x value that find-root used edit

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