It's a bit of a pain, and I haven't fully tested it, but try this
your-search-here | eval parts = split(input,"E") | eval part1 = tonumber(mvindex(parts,0)) | eval part2 = tonumber(mvindex(parts,1)) | eval dec = exact((part1) * pow(10,part2)) | fields - parts part1 part2
Substitute the name of your field for input in the search, and the resulting number number will be found in the dec field.
Now, I don't think that you want to type this in every time! So, create a macro. Here's how in the manual Create and Use Search Macros
Put the following into the macro definition:
eval parts = split($input$,"E") | eval part1 = tonumber(mvindex(parts,0)) | eval part2 = tonumber(mvindex(parts,1)) | eval $dec$ = exact((part1) * pow(10,part2)) | fields - parts part1 part2
Notice that I've modified the string slightly so that it becomes a macro with two arguments:
input - the name of the field that contains the string (the number in scientific notation
dec - the name of the field that will contain the resulting decimal number
If you name the macro
convert, then you can use it like this
your-search-here | `convert(sciNum,decNum)` | table sciNum, decNum
Note the use of the back-quote, not the single quote, around the macro. In the example, sciNum must be the name of your existing field. decNum will be created if it does not already exist.
tonumber() call works now in 6.x
... | eval sci_no="7.6e+02" | eval result=tonumber(sci_no)
yields result of