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Export FindRoot[ ] output to xls file?

Chenghua Deng
Posted 4 years ago

Hi everyone,

I just begin my Mathematica learning. I have a question about complex equation solving and data output. Details were showed below.

The equation is 6.429651.21663ln[1+0.00255(p0.1/x)^(1/1.21663)]+1.44638ln[1+0.26895p0.1/x]=4.498351.18924ln[1+0.00168(p0.9/(1-x))^(1/1.18924)]+0.85764ln[1+0.03736p0.9/(1-x)]

I know the range of p, and I need to get a set of solutions to the equation. The independent variable p is a positive number in the range of 0 to 100. I will select 25 numbers in this range and calculated the corresponding x. What's more, I wish the output data could be in the xls file which I could analysis it by other software.

Then I did the program showed in attachment.

I can see the results, however, I wish the out put xls could reflect the data more clearly and simple that one line could show the value p and another line could show the x. And each two corresponding values could be showed in the same row.

I wish you can give me some suggestions to rewrite the program more easily, especially the xls file output.

Thank you very much.
POSTED BY: Chenghua Deng
7 Replies
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Hans Milton
Hans Milton
Posted 4 years ago
POSTED BY: Hans Milton
Chenghua Deng
Chenghua Deng
Posted 4 years ago

Thank you very much.
POSTED BY: Chenghua Deng
Hans Milton
Hans Milton
Posted 4 years ago

Hi. Try this:

Export[
    "g.xls",
    Table[
     {n, p1, p2} /.
        FindRoot[
           {
          n == ((1.60856*0.73331*p1^(1/1.44247))/(1 + 0.73331*p1^(1/1.44247)) +
               (1.60856*0.73325*p1^(1/1.44239))/(1 + 0.73325*p1^(1/1.44239))) ==
         ((2.09702*0.07621*p2^(1/1.43739))/(1 + 0.07621*p2^(1/1.43739)) +
               (2.11532*5.11472*p2^(1/1.07083))/(1 + 5.11472*p2^(1/1.07083))) == h
          },
           {{n, h}, {p1, 0}, {p2, 0}}
        ],
     {h, 0, 3.2, 3.2/20}
    ]
 ]
POSTED BY: Hans Milton
Chenghua Deng
Chenghua Deng
Posted 4 years ago
POSTED BY: Chenghua Deng
Chenghua Deng
Chenghua Deng
Posted 4 years ago

Thank you very much.

Your method works pretty well. It satisfied all I need.
POSTED BY: Chenghua Deng
Hans Milton
Hans Milton
Posted 4 years ago

Or maybe this?

Export[
      "c.xls",
    Table[
     {
           p,
           x /.FindRoot[
           6.42965*1.21663*Log[1 + 0.00255*(p*0.1/x)^(1/1.21663)] +
               1.44638*Log[1 + 0.26895*p*0.1/x] ==
             4.49835*1.18924*Log[1 + 0.00168*(p*0.9/(1 - x))^(1/1.18924)] +
               0.85764*Log[1 + 0.03736*p*0.9/(1 - x)],
           {x, 0.1}
          ]
        },
     {p, 4, 100, 4}
    ]
 ]
POSTED BY: Hans Milton
Bill Nelson
Bill Nelson
Posted 4 years ago

Perhaps

Export["c.xls",Transpose[Table[{p,x}/.FindRoot[...
POSTED BY: Bill Nelson
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