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# tcl 8.5 floating point operation

## tcl 8.5 floating point operation

(OP)
Hi I am using tcl 8.5.
When I do division 1.0/1e-9 i get 999999999.9999999 instead of 1e9.
The same operation on tcl 8.4 works fine.
How to get around this problem to get the correct value/

for {set x 0} {$x<20} {incr x} { puts "$x [expr 1/1e-$x]"} ----------- OUTPUT ----------- 0 1.0 1 10.0 2 100.0 3 1000.0 4 10000.0 5 99999.99999999999 6 1000000.0 7 10000000.0 8 100000000.0 9 999999999.9999999 10 10000000000.0 11 100000000000.0 12 1000000000000.0 13 10000000000000.0 14 100000000000000.0 15 999999999999999.9 16 10000000000000000.0 17 1e+17 18 9.999999999999999e+17 19 1e+19 ### RE: tcl 8.5 floating point operation Use format, for example: #### CODE for {set x 0} {$x<20} {incr x} {
puts [format "%2d %g" $x [expr 1/1e-$x]]
}
outputs

00 1
01 10
02 100
03 1000
04 10000
05 100000
06 1e+006
07 1e+007
08 1e+008
09 1e+009
10 1e+010
11 1e+011
12 1e+012
13 1e+013
14 1e+014
15 1e+015
16 1e+016
17 1e+017
18 1e+018
19 1e+019

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