REM Program to calculate the new ephemeris for a binary star system.
REM (Basically a linear least squares fit adapted for this program set.)
REM By James Marshall (class of 1996), summer 1995, Villanova University
REM Last updated June 4, 1996
REM
CLS
PRINT "Ephemeris Calculator"
PRINT "~~~~~~~~~~~~~~~~~~~~"
PRINT
PRINT "This program will calculate a new ephemeris for both primary and secondary"
PRINT "minima of an eclipsing binary system by performing a least squares fit"
PRINT "on the data.  In addition to calculating the new values, it will also"
PRINT "find the standard deviation of the new time of minimum and period which"
PRINT "is useful in the analysis of the data."
PRINT
PRINT "It is best if you run the O-C program on the data first and then use"
PRINT "that output file (.o-c) as the input for this program.  However, the"
PRINT "option to input data by hand is still given."
PRINT
PRINT "<Press any key for further instructions>"
DO: anykey$ = INKEY$: LOOP WHILE anykey$ = ""
CLS
PRINT "Data Input"
PRINT "~~~~~~~~~~"
PRINT
PRINT "File name and path (no extension) of the .o-c input file (ENTER for none):"
INPUT "   "; inpfile1$
IF inpfile1$ <> "" THEN
 inpfile1$ = inpfile1$ + ".o-c"
 OPEN inpfile1$ FOR INPUT AS #1
 LINE INPUT #1, name$
 starname$ = ""
 WHILE LEFT$(name$, 1) <> "'"
  starname$ = starname$ + LEFT$(name$, 1)
  name$ = MID$(name$, 2)
 WEND
 LINE INPUT #1, none$
 LINE INPUT #1, tmin1$
 tmin1# = VAL(MID$(tmin1$, 21))
 LINE INPUT #1, p1$
 p1# = VAL(MID$(p1$, 21))
 LINE INPUT #1, numtmin1$
 numtmin1% = VAL(MID$(numtmin1$, 21))
 LINE INPUT #1, tmin2$
 tmin2# = VAL(MID$(tmin2$, 21))
 LINE INPUT #1, p2$
 p2# = VAL(MID$(p2$, 21))
 LINE INPUT #1, numtmin2$
 numtmin2% = VAL(MID$(numtmin2$, 21))
 LINE INPUT #1, none$
 LINE INPUT #1, by$
 LINE INPUT #1, none$
 LINE INPUT #1, none$
 LINE INPUT #1, none$
 LINE INPUT #1, none$
 DIM tminprim#(numtmin1%), tminsec#(numtmin2%), oc1#(numtmin1%)
 DIM oc2#(numtmin2%), epoch1#(numtmin1%), epoch2#(numtmin2%), day#(numtmin2%)
 FOR i = 1 TO numtmin1%
  INPUT #1, tminprim#(i), oc1#(i), epoch1#(i)
 NEXT i
 INPUT #1, none$
 INPUT #1, none$
 INPUT #1, none$
 INPUT #1, none$
 FOR i = 1 TO numtmin2%
  INPUT #1, tminsec#(i), oc2#(i), day#(i), epoch2#(i)
 NEXT i
 CLOSE #1
ELSE
 CLS
 PRINT "Input Data By Hand"
 PRINT "~~~~~~~~~~~~~~~~~~"
 PRINT
entry1:
 REM enter data by hand
 PRINT
 INPUT "        Star Name:  ", starname$
 INPUT "        T_min (I):  ", tmin1#
 INPUT "            P (I):  ", p1#
 INPUT "   # of T_min I's:  ", numtmin1%
 INPUT "       T_min (II):  ", tmin2#
 INPUT "           P (II):  ", p2#
 INPUT "  # of T_min II's:  ", numtmin2%
 PRINT
 INPUT "Emphemeris calculated by:  ", ephem$
 PRINT
 INPUT "Are all the values correct (Y/N)"; ans$
 IF (ans$ = "N" OR ans$ = "n") THEN GOTO entry1

 REM *** <INSERT ROUTINE HERE> ***
END IF
PRINT
PRINT "Thank you.  Press any key to continue."
DO: anykey$ = INKEY$: LOOP WHILE anykey$ = ""
CLS
REM epoch = x, tmin = y; period = slope, newtmin = y intercept
REM Find the new ephemeris (do the fit) and get errors
REM Primary
sumxy1# = sumx1# = sumy1# = sumx21# = sumy21# = 0!
FOR i = 1 TO numtmin1%
 sumxy1# = sumxy1# + (epoch1#(i) * tminprim#(i))
 sumx1# = sumx1# + epoch1#(i)
 sumy1# = sumy1# + tminprim#(i)
 sumx21# = sumx21# + (epoch1#(i) * epoch1#(i))
 sumy21# = sumy21# + (tminprim#(i) * tminprim#(i))
NEXT i
delta1# = numtmin1% * sumx21# - sumx1# * sumx1#
period1# = (numtmin1% * sumxy1# - sumx1# * sumy1#) / delta1#
newtmin1# = (sumx21# * sumy1# - sumx1# * sumxy1#) / delta1#
sum2line1# = 0!
FOR i = 1 TO numtmin1%
 term1# = (tminprim#(i) - newtmin1# - period1# * epoch1#(i))
 sum2line1# = sum2line1# + (term1# * term1#)
NEXT i
sigmay21# = (1 / (numtmin1% - 2)) * sum2line1#
sigmatmin1# = SQR(sigmay21# * sumx1# / delta1#)
sigmaper1# = SQR(numtmin1% * sigmay21# / delta1#)
REM Secondary
sumxy2# = sumx2# = sumy2# = sumx22# = sumy22# = 0!
FOR i = 1 TO numtmin2%
 sumxy2# = sumxy2# + (epoch2#(i) * tminsec#(i))
 sumx2# = sumx2# + epoch2#(i)
 sumy2# = sumy2# + tminsec#(i)
 sumx22# = sumx22# + (epoch2#(i) * epoch2#(i))
 sumy22# = sumy22# + (tminsec#(i) * tminsec#(i))
NEXT i
delta2# = numtmin2% * sumx22# - sumx2# * sumx2#
period2# = (numtmin2% * sumxy2# - sumx2# * sumy2#) / delta2#
newtmin2# = (sumx22# * sumy2# - sumx2# * sumxy2#) / delta2#
sum2line2# = 0!
FOR i = 1 TO numtmin2%
 term2# = (tminsec#(i) - newtmin2# - period2# * epoch2#(i))
 sum2line2# = sum2line2# + (term2# * term2#)
NEXT i
sigmay22# = (1 / (numtmin2% - 2)) * sum2line2#
sigmatmin2# = SQR(sigmay22# * sumx2# / delta2#)
sigmaper2# = SQR(numtmin2% * sigmay22# / delta2#)
REM Results
CLS
PRINT "Results"
PRINT "~~~~~~~"
PRINT
PRINT "For primary eclipse:"
PRINT "    Tmin (I) = "; USING "#######.#######"; newtmin1#
PRINT " Uncertainty = "; USING "#######.#######"; sigmatmin1#
PRINT "  Period (I) = "; USING "##.#######"; period1#
PRINT " Uncertainty = "; USING "##.#######"; sigmaper1#
PRINT
PRINT "For secondary eclipse:"
PRINT "   Tmin (II) = "; USING "#######.#######"; newtmin2#
PRINT " Uncertainty = "; USING "#######.#######"; sigmatmin2#
PRINT " Period (II) = "; USING "##.#######"; period2#
PRINT " Uncertainty = "; USING "##.#######"; sigmaper2#
PRINT
PRINT "Press any key to continue"
DO: anykey$ = INKEY$: LOOP WHILE anykey$ = ""
REM END IF
REM print to file
CLS
PRINT "Thank you for using this ephemeris calculator."
PRINT
INPUT "Would you like to save the results to a file (Y/N)"; ans$
IF (ans$ = "N" OR ans$ = "n") THEN GOTO skipit
PRINT "Enter the filename with path (.eph extension automatic):  "
PRINT "   "; : INPUT file$
OPEN file$ + ".eph" FOR OUTPUT AS #1
PRINT #1, starname$; "'s Ephemeris Information"
PRINT #1, ""
PRINT #1, "For primary eclipse:"
PRINT #1, "    Tmin (I) = "; USING "#######.#######"; newtmin1#
PRINT #1, " Uncertainty = "; USING "#######.#######"; sigmatmin1#
PRINT #1, "  Period (I) = "; USING "##.#######"; period1#
PRINT #1, " Uncertainty = "; USING "##.#######"; sigmaper1#
PRINT #1, ""
PRINT #1, "For secondary eclipse:"
PRINT #1, "   Tmin (II) = "; USING "#######.#######"; newtmin2#
PRINT #1, " Uncertainty = "; USING "#######.#######"; sigmatmin2#
PRINT #1, " Period (II) = "; USING "##.#######"; period2#
PRINT #1, " Uncertainty = "; USING "##.#######"; sigmaper2#
CLOSE #1
skipit:
PRINT
PRINT "Have a nice day!  :)"
END