added demonstration of mixing error in PK

pk/mixingerror/fdg.bld

+time[minutes]	1[kBq/cc]
+0.23300	2.100000e-02
+0.55000	2.266900e+01
+0.76700	1.234900e+02
+1.00000	1.020310e+02
+1.25000	7.589800e+01
+1.50000	5.056600e+01
+1.75000	4.181500e+01
+2.00000	3.787000e+01
+2.33300	3.707600e+01
+2.66700	3.519600e+01
+3.00000	3.243600e+01
+4.00000	2.819300e+01
+5.00000	2.396400e+01
+7.50000	1.557100e+01
+10.00000	1.162600e+01
+15.00000	7.459000e+00
+20.00000	5.099000e+00
+30.00000	2.722000e+00
+40.06700	1.784000e+00
+50.20000	1.111000e+00
+60.00000	8.960000e-01
+70.00000	6.580000e-01
+79.96700	5.190000e-01
+90.03300	4.960000e-01
+100.00000	4.290000e-01
+110.00000	3.920000e-01
+# Isotope := F-18
+# Radiotracer: FDG
+# Sampling := arterial plasma

pk/mixingerror/readme.txt

+Example of mixing error
+=======================
+
+In PK studies plasma sampling is usually started a few minutes after bolus injection.
+This can lead to so called mixing error or bolus error.
+This example from a FDG study aims to demonstrate the error, or, to show that it can be negligible.
+See http://www.turkupetcentre.net/petanalysis/input_pk.html

pk/mixingerror/sim.sh

+#!/bin/bash
+#: Title      : Mixing error
+#: Date       : 2019-02-13
+#: Author     : "Vesa Oikonen" <vesa.oikonen@utu.fi>
+#: Options    : None
+
+
+printf "\n=====================================================================\n"
+printf "  Making or emptying result folder to not mess with data and script \n"
+if [ ! -d res ]; then
+  mkdir res
+else
+  rm -f res/*
+fi
+
+printf "\n=====================================================================\n"
+printf "  Cut off samples before 2 min to simulate traditional PK plasma data \n"
+printf "=====================================================================\n"
+
+taccut fdg.bld 2 99999 res/pk.bld
+if [ $? -ne 0 ] ; then printf "Failed!\n" ; exit 1 ; fi
+printf "\n ok \n"
+
+printf "\n=====================================================================\n"
+printf "  Fit sum-of-exponentials function to it. \n"
+printf "  Three exponentials are needed to get decent fit in this case. \n"
+printf "  Plot fitted TAC and data starting from 2 min. \n"
+printf "=====================================================================\n"
+
+fit_dexp -3 res/pk.bld res/pk.par
+if [ $? -ne 0 ] ; then printf "Failed!\n" ; exit 1 ; fi
+printf "\n ok \n"
+
+fit2dat -c=2,111,0.1 res/pk.par res/pkfit2.bld
+if [ $? -ne 0 ] ; then printf "Failed!\n" ; exit 1 ; fi
+printf "\n ok \n"
+tac2svg -mt="" -yt="" res/pkfit.svg -s res/pk.bld -l res/pkfit2.bld
+if [ $? -ne 0 ] ; then printf "Failed!\n" ; exit 1 ; fi
+printf "\n ok \n"
+
+
+printf "\n=====================================================================\n"
+printf "  Plot fitted and original TACs starting from zero time until 10 min. \n"
+printf "=====================================================================\n"
+
+fit2dat -a=15 res/pk.par res/pkfit.bld
+if [ $? -ne 0 ] ; then printf "Failed!\n" ; exit 1 ; fi
+printf "\n ok \n"
+
+tac2svg -mt="" -yt="" -x2=10 res/pk10.svg fdg.bld -l res/pkfit.bld
+if [ $? -ne 0 ] ; then printf "Failed!\n" ; exit 1 ; fi
+printf "\n ok \n"
+
+printf "\n=====================================================================\n"
+printf "  Calculate AUCs before 2 min from fitted and original TAC. \n"
+printf "=====================================================================\n"
+
+printf "\nDot-to-dot AUC 0-2 min\n"        > res/auc.txt
+interpol -i -x=2 -header=no fdg.bld       >> res/auc.txt
+if [ $? -ne 0 ] ; then printf "Failed!\n" ; exit 1 ; fi
+printf "Exp fit AUC 0-2 min\n"            >> res/auc.txt
+interpol -i -x=2 -header=no res/pkfit.bld >> res/auc.txt
+if [ $? -ne 0 ] ; then printf "Failed!\n" ; exit 1 ; fi
+cat res/auc.txt
+
+printf "\n===================================================================\n"
+printf "   All done! \n"
+printf "===================================================================\n"
+exit 0