# -*- tcl -*-
# Tests for filters library.
#
# RCS: @(#) $Id: geometry.test,v 1.13 2010/04/06 17:02:25 andreas_kupries Exp $

# -------------------------------------------------------------------------

source [file join \
	[file dirname [file dirname [file join [pwd] [info script]]]] \
	devtools testutilities.tcl]

testsNeedTcl     8.6
testsNeedTcltest 1.0

support {
    useLocal math.tcl math
}
testing {
    useLocal filtergen.tcl math::filters
}

# -------------------------------------------------------------------------

proc withFourDecimals {args} {
    set res {}
    foreach arg $args {lappend res [expr (round(10000*$arg))/10000.0]}
    return $res
}

if { [info commands lmap] eq {} } {
    proc lmap {var list body} {
        upvar 1 $var _$var
        set __$var {}
        foreach _$var $list {
            lappend __$var [uplevel 1 $body]
        }
        set __$var
    }
}

#
# Custom matching procedure:
# Expect an accuracy of at least four decimals
#
proc matchNumbers {expected actual} {
    set match 1
    foreach a $actual e $expected {
        if { [llength $a] == 1 } {
            if {abs($a-$e) > 1.0e-4} {
                set match 0
                break
            }
        } else {
            set match [matchNumbers $a $e]
        }
    }
    return $match
}

customMatch numbers matchNumbers


# -------------------------------------------------------------------------

# Butterworth filter coefficients

test butterworth-1.1 {low-pass, second order} -match numbers -body {
    set coeffs [::math::filters::filterButterworth 1 2 100 20]
    set result [concat {*}$coeffs]
} -result {1.0 2.0 1.0 1.78885 -0.94793 4.84093}

test butterworth-1.2 {high-pass, second order} -match numbers -body {
    set coeffs [::math::filters::filterButterworth 0 2 100 20]
    set result [concat {*}$coeffs]
} -result {1.0 -2.0 1.0 0.94427 -0.50038 2.55535}


# Actually filter data

# 20 data, second-order filter, so 18 data returned
test filter-1.0 {low-pass, second order, uniform series} -match numbers -body {
    set coeffs   [::math::filters::filterButterworth 1 2 100 20]
    set data     [lrepeat 20 1.0]
    set filtered [::math::filters::filter $coeffs $data]
    set result   [list [llength $filtered] [lindex $filtered end]]
} -result {18 1.0}

test filter-1.1 {low-pass, second order, sine series} -match numbers -body {
    set coeffs   [::math::filters::filterButterworth 1 2 100 20]

    set twopi  [expr {2.0 * acos(-1.0)}]
    set period 100

    set data {}

    for {set i 0} {$i < $period} {incr i} {
        lappend data [expr {cos($twopi * ($i/1.0) / double($period))}]
    }

    set filtered [lrange [::math::filters::filter $coeffs $data] end-7 end]
} -result {0.845195 0.877086 0.905515 0.930371 0.951555 0.968984 0.982588 0.992315}

# The object interface

test filterobj-1.0 {low-pass, second order, sine series} -match numbers -body {
    set coeffs   [::math::filters::filterButterworth 1 2 100 20]
    set filter   [::math::filters::filterObject new $coeffs]

    set twopi  [expr {2.0 * acos(-1.0)}]
    set period 100

    set data {}

    for {set i 0} {$i < $period} {incr i} {
        lappend filtered [$filter filter [expr {cos($twopi * ($i/1.0) / double($period))}]]
    }

    set filtered [lrange $filtered end-9 end]
} -result {0.771545 0.809968 0.845195 0.877086 0.905515 0.930371 0.951555 0.968984 0.982588 0.992315}


#
# Cleanup
#
testsuiteCleanup