Need help in antilog calculation in excel

[shashibioinfo143]

Dear sir/mam,


i have query regarding antilog value calculation.


i have values of -log10(pvalue) and i want Pvalue


so value of -log10(pvalue) as x


and divide by 10 so it is x/10 and -(x/10)


used POWER function to calculate antilog value POWER(10, -(x/10))


POWER(10, -(17.70776/10)) i got value 0.016952 but when i reverse i.e when i use this value in -log10(pvalue) formula i get 1.77076 value is it correct way to do


need help


Thank you

 

[Eric W]

Welcome to the forum.

Some of your intermediate steps I don't understand. Given a value in A1, and the -LOG10 function in B1, then the formula in C1 is the inverse of B1 and returns A1.

	A	B	C

<colgroup><col style="width: 25pxpx"><col><col><col></colgroup><thead>
</thead><tbody>
[TD="align: center"]1[/TD]
[TD="align: right"]0.016952[/TD]
[TD="align: right"]1.770779[/TD]
[TD="align: right"]0.016952[/TD]

</tbody>

Sheet2​

[TABLE="width: 85%"]
<tbody>[TR]
[TD]Worksheet Formulas[TABLE="width: 100%"]
<thead>[TR="bgcolor: #DAE7F5"]
[TH="width: 10px"]Cell[/TH]
[TH="align: left"]Formula[/TH]
[/TR]
</thead><tbody>[TR]
[TH="width: 10px, bgcolor: #DAE7F5"]B1[/TH]
[TD="align: left"]=-LOG10(A1)[/TD]
[/TR]
[TR]
[TH="width: 10px, bgcolor: #DAE7F5"]C1[/TH]
[TD="align: left"]=POWER(10,-B1)[/TD]
[/TR]
</tbody>[/TABLE]
[/TD]
[/TR]
</tbody>[/TABLE]

 

[shashibioinfo143]

i know the value of z in formula Z=-LOG10(x) now i need value of X so i used formula X = POWER(10, -(Z/10)) so i got some value of X but when i used X value again in formula Z =-LOG10(x) im getting one point below for example.

11.29558 =-LOG10(X)

when i used X = POWER(10, -(11.29558/10)) i got value of X as 0.0742

but when i used X value in formula =-LOG10(x) i get value 1.1295960947 point value is shifted.

Need help

Thank you

Welcome to the forum.

Some of your intermediate steps I don't understand. Given a value in A1, and the -LOG10 function in B1, then the formula in C1 is the inverse of B1 and returns A1.

	A	B	C

<tbody>
[TD="align: center"]1[/TD]
[TD="align: right"]0.016952[/TD]
[TD="align: right"]1.770779[/TD]
[TD="align: right"]0.016952[/TD]

</tbody>

Sheet2​

[TABLE="width: 85%"]
<tbody>[TR]
[TD]Worksheet Formulas[TABLE="width: 100%"]
<tbody>[TR="bgcolor: #DAE7F5"]
[TH]Cell[/TH]
[TH="align: left"]Formula[/TH]
[/TR]
[TR]
[TH="bgcolor: #DAE7F5"]B1[/TH]
[TD="align: left"]=-LOG10(A1)[/TD]
[/TR]
[TR]
[TH="bgcolor: #DAE7F5"]C1[/TH]
[TD="align: left"]=POWER(10,-B1)[/TD]
[/TR]
</tbody>[/TABLE]
[/TD]
[/TR]
</tbody>[/TABLE]

 

[Eric W]

Don't divide by 10.