Approximate the value of e using the power series expansion

e-power-series.tcl

#!/usr/bin/tclsh

#
# approximate e using the power series expansion
#

proc approx_e {{n 20}} {
    set value 1
        set factorial 1
        set i 1

        while {$i <= $n} {
            set factorial [expr {$factorial * $i}]
                set value [expr {$value + 1.0/$factorial}]
                incr i
        }

    return $value
}


puts [approx_e]

# ex: ts=4 sw=4 et filetype=tcl noexpandtab