# pretty print from autoindent and ased editor
        # Ideal Rocket Performance calculator
        # Ideal Rocket Velocity treats no atmospheric drag, uses simple
        # assumptions & formulas, other accuracy issues.
        # assumption, rocket cross section == nozzle throat area.
        # Reported different velocity quantities 
        # involve different assumptions and formulas.
        # Major velocity loss terms are 1) drag loss,
        # 2) gravity loss, 3) nozzle efficiency
        # and 4) loss to inefficient trajectory path (subset of drag). 
        # Intention is to estimate various known
        # velocity losses from ideal velocity.
        # Need to collect some rocket examples in metric units.
        # written on Windows XP on TCL
        # working under TCL version 8.6
        # gold on  TCL Club, 6Sep2018
        package require Tk
        namespace path {::tcl::mathop ::tcl::mathfunc}
        frame .frame -relief flat -bg aquamarine4
        pack .frame -side top -fill y -anchor center
        set names {{} {initial mass1, kg :} }
        lappend names {final mass2, burnout mass,  kg  :}
        lappend names {Isp, specific impulse, seconds: }
        lappend names {constant thrust, kg*meter/sec*sec:}
        lappend names {optional, rocket diameter, meters:}
        lappend names {optional, drag_coefficient, for metric units: }
        lappend names {rocket mass ratio, no units: }
        lappend names {Ideal Rocket Velocity, meters per second:}
        foreach i {1 2 3 4 5 6 7 8} {
            label .frame.label$i -text [lindex $names $i] -anchor e
            entry .frame.entry$i -width 35 -textvariable side$i
            grid .frame.label$i .frame.entry$i -sticky ew -pady 2 -padx 1 }
        proc about {} {
            set msg "Calculator for Ideal Rocket Performance
            from TCL "
            tk_messageBox -title "About" -message $msg }
        proc pi {} {expr acos(-1)}
        proc degtoradiansconst {} {return [ expr {180./[pi]}  ]}
        proc radianstodegconst {} {return [ expr {[pi]/180.}  ]}
        proc calculate {     } {
            global answer2
            global side1 side2 side3 side4 side5
            global side6 side7 side8
            global mass1 mass2 Isp1 thrust1 acc_ratio
            global acc_01 mass_ratio1 time_b1 ideal_rocket_velocity1
            global rocket_efficiency1 cross_section_area1
            global velocity_if_constant_acceleration1 velocity_if_gravity_losses1
            global  prelim_flow_rate1 prelim_avg_drag_loss1
            global ballistic_range1 ballistic_altitude1 ballistic_duration1
            global theoretical_exhaust_velocity1 prelim_vertical_velocity1
            global testcase_number
            incr testcase_number
            set side1 [* $side1 1. ]
            set side2 [* $side2 1. ]
            set side3 [* $side3 1. ]
            set side4 [* $side4 1. ]
            set side5 [* $side5 1. ]
            set side6 [* $side6 1. ]
            set side7 [* $side7 1. ]
            set side8 [* $side8 1. ]
            set gravity 9.8
            set mass1 $side1
            set mass2 $side2
            set Isp1 $side3
            set thrust1 $side4
            set diameter1 $side5
            set drag_coefficient1 side6
            # inital assumption == variable acceleration over rocket burn
            proc circlearea2 {diameter} { 
            return  [  expr { 0.25*[pi]*($diameter**2) }]}
            proc ideal_rocket_velocity { gravity Isp1 mass1 mass2} {
            return [ expr { $gravity*$Isp1*log($mass1/$mass2)}]}
            proc mass_ratio {mass1 mass2} {return [ expr { $mass1 / $mass2 }]}
            proc acc_0 {thrust mass1} { return [ expr {  ($thrust*1.) / $mass1 }]}
            proc rocket_efficiency {mass_ratio acc_0} {
            return [expr {(2.*($mass_ratio-1.))/($acc_0*$mass_ratio*1.)}]}
            proc theoretical_exhaust_velocity { Isp1 gravity} {
            return [* $Isp1 $gravity ]  }
            proc time_b {mass_ratio Isp acc_0} {
            return [expr {(($mass_ratio-1.)/($acc_0*$mass_ratio*1.))*$Isp}]}           
            set ideal_rocket_velocity1 [ ideal_rocket_velocity $gravity $Isp1 $mass1 $mass2  ]
            set cross_section_area1 [ circlearea2  $diameter1    ]
            set mass_ratio1 [ mass_ratio $mass1 $mass2  ]
            set acc_01 [ acc_0 $thrust1 $mass1   ]
            set rocket_efficiency1 [ rocket_efficiency $mass_ratio1 $acc_01 ]
            set theoretical_exhaust_velocity1 { theoretical_exhaust_velocity $Isp1 $gravity }
            set time_b1 [ time_b $mass_ratio1 $Isp1 $acc_01 ]
            set prelim_flow_rate1 [/ [- $mass1 $mass2] $time_b1 ]
            # preliminary >> ideal<<<  altitude of
            # assumed vertical launch over burntime,
            # no cross winds & no drag, order of magnitude calc. 
            # & many assumptions, altiude in abs meters
            # assumed constant mass fraction rate expelled,
            # val < flow_rate1 / $mass1 > = fraction/sec
            proc vertical_velocity_no_drag { gravity time_b1 Isp1 prelim_flow_rate1 mass1 } {
            set time $time_b1 
            set mass_fraction_rate [/ $prelim_flow_rate1 $mass1  ]
            set quantity [ expr { $mass1 / ($mass1-$mass1*$mass_fraction_rate*$time)}]
            puts " testing $mass1 $mass_fraction_rate $time "
            set vert_velocity1 1
            set vert_velocity1 [ expr { ($gravity*$Isp1*log($quantity)) - ($gravity*$time) }] 
            return $vert_velocity1}  
            set prelim_vertical_velocity1 1
            set prelim_vertical_velocity1 [ vertical_velocity_no_drag  $gravity $time_b1 $Isp1 $prelim_flow_rate1 $mass1 ]
            # avg_drag_loss is flakey here, 
            # drag_c, combo rel. atmo. pressure,
            # back_pressure, and velocity vary over time.
            # average drag in order of magnitude,
            # in absolute value,  m/s velocity +- 30 percent
            # preliminary average drag loss over burntime,
            # absolute value & many assumptions, meters/second
            set v $ideal_rocket_velocity1
            set prelim_avg_drag_loss1 [* .5  $time_b1 [/ 1. $mass1 ] [* .5 .3 $cross_section_area1  $v $v ]] 
            proc velocity_if_gravity_losses { gravity time_b1 Isp1 mass1 mass2} {
            return [ expr { (9.8*$Isp1*log($mass1/$mass2)) - $gravity*$time_b1 }]}
            set velocity_if_gravity_losses1 [ velocity_if_gravity_losses $gravity $time_b1 $Isp1 $mass1 $mass2 ]
            # >>>>> WARNING!!!!  CHANGING ASSUMPTIONS HERE <<<<<<<
            # following cards change initial assumption ( acc. variable)
            # to constant acceleration rocket.
            # c. acc. rocket. has different velocity profile.
            # uses ratio of initial acceleration over gravity (9.8 m/s*s)
            set acc_ratio [/ [* $acc_01 $gravity] $gravity ]
            proc velocity_constant_acceleration {acc_ratio Isp1 mass1 mass2} {
            return [ expr { 9.8*$Isp1*($acc_ratio/($acc_ratio+1.))*log($mass1/$mass2)}]}
            set velocity_if_constant_acceleration1 [ velocity_constant_acceleration $acc_ratio $Isp1 $mass1 $mass2  ]
            set v $ideal_rocket_velocity1
            set launch_angle [* -1. 45. [degtoradiansconst ] 2.]
            proc ballistic_range { gravity  v  launch_angle} {return [ expr {  $v*$v*sin($launch_angle)/$gravity }]}
            set ballistic_range1 [ ballistic_range  $gravity $v $launch_angle ]
            set launch_angle [*  45. [degtoradiansconst ] ]
            proc ballistic_altitude { gravity  v  launch_angle} {return [ expr {  ($v*$v*sin($launch_angle)*sin($launch_angle))/(2.*$gravity) }]}
            set ballistic_altitude1 [ ballistic_range  $gravity $v $launch_angle ]
            proc ballistic_duration { gravity  v  launch_angle} {return [ expr {  (2.*$v*sin($launch_angle))/$gravity }]}
            set ballistic_duration1 [ ballistic_duration  $gravity $v $launch_angle ]
            # Running out of slots on screen, send other results to reportx proc
            set side7 $mass_ratio1
            set side8 $ideal_rocket_velocity1
        }
        proc fillup {aa bb cc dd ee ff gg hh} {
            .frame.entry1 insert 0 "$aa"
            .frame.entry2 insert 0 "$bb"
            .frame.entry3 insert 0 "$cc"
            .frame.entry4 insert 0 "$dd"
            .frame.entry5 insert 0 "$ee"
            .frame.entry6 insert 0 "$ff"
            .frame.entry7 insert 0 "$gg"
            .frame.entry8 insert 0 "$hh"
        }
        proc clearx {} {
            foreach i {1 2 3 4 5 6 7 8 } {
                .frame.entry$i delete 0 end } }
        proc reportx {} {
            global side1 side2 side3 side4 side5
            global side6 side7 side8
            global mass1 mass2 Isp1 thrust1 acc_ratio
            global acc_01 mass_ratio1 time_b1 ideal_rocket_velocity1
            global rocket_efficiency1 cross_section_area1
            global velocity_if_constant_acceleration1 velocity_if_gravity_losses1
            global  prelim_flow_rate1 prelim_avg_drag_loss1
            global theoretical_exhaust_velocity1 prelim_vertical_velocity1
            global ballistic_range1 ballistic_altitude1 ballistic_duration1
            global testcase_number
            console eval {.console config -bg palegreen}
            console eval {.console config -font {fixed 20 bold}}
            console eval {wm geometry . 40x20}
            console eval {wm title . "Ideal Rocket Performance Report, cut and paste from console 2"}
            console eval {. configure -background orange -highlightcolor brown -relief raised -border 30}
            console show;
            puts "%|table $testcase_number|printed in| tcl format|% "
            puts "&| quantity| value| comment, if any|& "
            puts "&| testcase number:|$testcase_number | |&"
            puts "&| $side1 :|initial launch cmass1 kg |   |&"
            puts "&| $side2 :|final mass2, burnout mass2 kg | |& "
            puts "&| $side3 :|Isp, specific impulse, seconds| |& "
            puts "&| $side4 :|constant thrust, kg*meter/sec*sec| |&"
            puts "&| $side5 :|optional, rocket diameter, meters: | |&"
            puts "&| $side6 :|optional, drag_coefficient, for metric units: | |&"
            puts "&| $cross_section_area1 :|rocket cross_section_area1,  meter**2: | |&"
            puts "&| $acc_01 :|initial acceleration, normalized to gravities: | |&"
            puts "&| $rocket_efficiency1 :|rocket_efficiency (ideal!, careful) , no units : | |&"
            puts "&| $velocity_if_constant_acceleration1 :|velocity_if_constant_acceleration (diff. assumptions!, careful) , meters/sec : | |&"
            puts "&| $velocity_if_gravity_losses1 :|velocity_if__gravity_losses  (diff. assumptions!, careful) , meters/sec : | |&"
            puts "&| $time_b1 :|rocket burn out time, Tf, seconds |  |&"
            puts "&| $theoretical_exhaust_velocity1 :|theoretical_exhaust_velocity, meter/sec |  |&"
            puts "&| $prelim_flow_rate1 :|preliminary mass flow rate, kg/second |  |&"
            puts "&| $prelim_avg_drag_loss1 :|preliminary average drag loss,abs & assumptions, meters/second |  |&"
            puts "&| $prelim_vertical_velocity1 :|preliminary vertical velocity,assumed vertical launch, meters/second |  |&"
            puts "&| $ballistic_range1 :|ballistic_range meters |  |&"
            puts "&| $ballistic_altitude1 :|ballistic_altitude meters |  |&"
            puts "&| $ballistic_duration1 :|ballistic_duration seconds |  |&"
            puts "&| $side7 :|mass ratio, no units |  |&"
            puts "&| $side8 :|Ideal Rocket velocity, meters/second|  |&"
            puts "testing $side1 $side2 $side3 $side4 $side5 $side6 $side7 $side8"
            puts "testing $Isp1 [expr ($acc_ratio/($acc_ratio+1.))] $acc_ratio $acc_01 $mass1 $mass2 "
        }
        frame .buttons -bg aquamarine4
        ::ttk::button .calculator -text "Solve" -command { calculate   }
        ::ttk::button .test2 -text "Testcase1" -command {clearx;fillup 16840. 7840. 225. 30000.0  1.0 0.3 2.2 1680.0}
        ::ttk::button .test3 -text "Testcase2" -command {clearx;fillup 13000. 6500. 237. 25000.0  1.0 0.3 2.2 1614.0}
        ::ttk::button .test4 -text "Testcase3" -command {clearx;fillup 15000. 6500. 225. 25000.0  1.0 0.3 2.3 1850.0}
        ::ttk::button .clearallx -text clear -command {clearx }
        ::ttk::button .about -text about -command about
        ::ttk::button .cons -text report -command { reportx }
        ::ttk::button .exit -text exit -command {exit}
        pack .calculator  -in .buttons -side top -padx 10 -pady 5
        pack  .clearallx .cons .about .exit .test4 .test3 .test2   -side bottom -in .buttons
        grid .frame .buttons -sticky ns -pady {0 10}
        . configure -background aquamarine4 -highlightcolor brown -relief raised -border 30
        wm title . "Ideal Rocket Performance Formula Calculator"
        # This code is copyrighted same as TCL version 8.6
        # 6sep2018 copyrighted under and same as TCL license.
        # Editorial rights and disclaimers 
        # are reserved under TCL license.
        # Gold on  TCL club, 6Sep2018