Updated 2017-03-09 23:26:02 by gold

Introduction edit

gold Here is some eTCL starter code for calculating profits from piece wise production and sales, includes flat percentage tax. The impetus for these calculations was calculating profits from antenna sales. Most of the testcases involve modeled data, using assumptions and rules of thumb.

Total costs equal number of units times production cost per unit. Total sales equal number of units times selling price per unit. Total profits equal total sales minus total costs. Total profits equal total profits minus (tax percentage/100.) times total profits.

Pseudocode and Equations

```  total costs = number of units * production cost per unit
total sales = number of units * selling price per unit.
total profits = total sales - total costs
total profits = total profits - total profits * (tax percentage/100)
price? = raw materials + labor  +  profit
price? = raw materials + heat process
price? = raw materials + labor
average price per unit  = revenue  / units sold```

Testcases Section

In planning any software, it is advisable to gather a number of testcases to check the results of the program. The math for the testcases can be checked by pasting statements in the TCL console. Aside from the TCL calculator display, when one presses the report button on the calculator, one will have console show access to the capacity functions (subroutines).

Testcase 1

1 table printed in tcl wiki format
quanity value comment, if any
testcase number 1
selling price per unit: 100.
number of units: 50.
production cost per unit: 65.0
taxes percent % : 0.0
answers: total costs: 5000.0
total sales: 3250.0
total profits dollars : 1750.0

Testcase 2

2table printed in tcl wiki format
quanity value comment, if any
testcase number 2
selling price per unit: 100.
number of units: 50.
production cost per unit: 65.0
taxes percent % : 10.0
answers: total costs: 5000.0
total sales: 3250.0
total profits dollars : 1575.0

Testcase 3

3 table printed in tcl wiki format
quanity value comment, if any
testcase number 3
selling price per unit: 100.
number of units: 50.
production cost per unit: 65.
taxes percent % : 20.
answers: total costs: 5000.0
total sales: 3250.0
total profits dollars : 1400.0

References:

• Profit and Loss formulas [www.sciencehq.com/math-formulas/profit-and-loss-formulas.html]

Appendix Code edit

appendix TCL programs and scripts

```        # pretty print from autoindent and ased editor
# Piece wise profits calculator
# written on Windows XP on eTCL
# working under TCL version 8.5.6 and eTCL 1.0.1
# gold on TCL WIKI , 10apr2014
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 {{} { selling price per unit:} }
lappend names { number of units:}
lappend names { production cost per unit: }
lappend names { taxes percent % : }
lappend names {answers: total costs dollars:}
lappend names {total sales dollars:}
lappend names {profits dollars:}
foreach i {1 2 3 4 5 6 7} {
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 Piece Wise Profits
from TCL WIKI,
written on eTCL "
tk_messageBox -title "About" -message \$msg }
proc calculate {     } {
global side1 side2 side3 side4 side5
global side6 side7 testcase_number
incr testcase_number
set selling   \$side1
set unitsnum  \$side2
set costunits \$side3
set taxepct     \$side4
set side5 [* \$side1 \$side2 ]
set side6 [* \$side3 \$side2 ]
set profits [- [* \$side1 \$side2 ] [* \$side3 \$side2 ] ]
set totaltax [* \$profits [/ \$taxepct 100. ]]
set profits [- \$profits \$totaltax]
set side7 \$profits
}
proc fillup {aa bb cc dd ee ff gg} {
.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"}
proc clearx {} {
foreach i {1 2 3 4 5 6 7} {
.frame.entry\$i delete 0 end } }
proc reportx {} {
global side1 side2 side3 side4 side5
global side6 side7 testcase_number
console show;
puts "%|table printed in| tcl wiki format|% "
puts "&|quanity| value| comment, if any|& "
puts "&|testcase number| \$testcase_number||& "
puts "&| selling price per unit:| \$side1 ||&"
puts "&| number of units:| \$side2||& "
puts "&| production cost per unit:| \$side3||& "
puts "&| taxes percent % :| \$side4 ||&"
puts "&| answers: total costs:| \$side5||& "
puts "&| total sales:| \$side6 ||&"
puts "&| total profits dollars :| \$side7 ||&"
}
frame .buttons -bg aquamarine4
::ttk::button .calculator -text "Solve" -command { calculate   }
::ttk::button .test2 -text "Testcase1" -command {clearx;fillup 100. 50. 65.0  0.0 5000.0 3250.  1750. }
::ttk::button .test3 -text "Testcase2" -command {clearx;fillup 100. 50. 65.0  10.0 5000.0 3250.  1575. }
::ttk::button .test4 -text "Testcase3" -command {clearx;fillup 100. 50. 65. 20. 5000. 3250.   1400.0}
::ttk::button .clearallx -text clear -command {clearx }
::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 . "Piece wise profits"

```

Pushbutton Operation

For the push buttons, the recommended procedure is push testcase and fill frame, change first three entries etc, push solve, and then push report. Report allows copy and paste from console.

For testcases in a computer session, the eTCL calculator increments a new testcase number internally, eg. TC(1), TC(2) , TC(3) , TC(N). The testcase number is internal to the calculator and will not be printed until the report button is pushed for the current result numbers (which numbers will be cleared on the next solve button.) The command { calculate; reportx } or { calculate ; reportx; clearx } can be added or changed to report automatically. Another wrinkle would be to print out the current text, delimiters, and numbers in a TCL wiki style table as
```  puts " %| testcase \$testcase_number | value| units |comment |%"
puts " &| volume| \$volume| cubic meters |based on length \$side1 and width \$side2   |&"  ```