Sparkline is a term Edward Tufte invented with for "small, high resolution graphics embedded in a context of words, numbers, images". On the Internet, however, the term has come to often mean rough text charts made with block characters, like this: ▁▂▃▅▂▇.
dbohdan 2014-12-29: This particular implementation was inspired by using one for Bash (sadly incompatible with POSIX sh). It works in both Tcl 8.5+ (a least) and Jim Tcl.
namespace eval sparklines {
namespace export create
variable version 0.0.1
variable ticks [list ▁ ▂ ▃ ▄ ▅ ▆ ▇ █]
variable tickCount [expr {[llength $ticks] - 1}]
proc create data {
variable ticks
variable tickCount
set sorted [lsort -real $data]
set min [lindex $sorted 0]
set max [lindex $sorted end]
set result {}
foreach x $data {
set xNormalized [expr {
int($tickCount * ($x - $min) / ($max - $min))
}]
append result [lindex $ticks $xNormalized]
}
return $result
}
}
puts [sparklines::create {1 5 22 13 53}] ;# ▁▁▃▂█
puts [sparklines::create {0 30 55 80 33 150}] ;# ▁▂▃▄▂█
puts [sparklines::create {9 13 5 17 1}] ;# ▄▆▂█▁