Test of Calculation of x,y values
From Tauwiki
New Calc_xy method updated on 27-8-07:
The x, y values created by new and old methods have been compared. The new method uses floats for W,S,Z gains, offsets, shifts and scales.
Old Method:
X Y
8.290000E+02 5.150000E+02
8.300000E+02 5.140000E+02
8.290000E+02 5.130000E+02
8.300000E+02 5.140000E+02
8.280000E+02 5.160000E+02
8.300000E+02 5.130000E+02
8.320000E+02 5.120000E+02
8.300000E+02 5.140000E+02
8.310000E+02 5.150000E+02
8.320000E+02 5.140000E+02
8.290000E+02 5.100000E+02
8.330000E+02 5.150000E+02
8.300000E+02 5.120000E+02
New Method:
X Y
8.295696E+02 5.152405E+02
8.307311E+02 5.140302E+02
8.290875E+02 5.138235E+02
8.302264E+02 5.140269E+02
8.282591E+02 5.160443E+02
8.304019E+02 5.130146E+02
8.322032E+02 5.120000E+02
8.302264E+02 5.140269E+02
8.310607E+02 5.150464E+02
8.323814E+02 5.142376E+02
8.297441E+02 5.109861E+02
8.337063E+02 5.150561E+02
8.300729E+02 5.120000E+02
8.302264E+02 5.140269E+02
8.304019E+02 5.130146E+02
8.300729E+02 5.152457E+02
The x,y values calculated by UVS_calc_xy module found in fits files (level_g]]) of pipeline run and those in the input file (simulation output file) have been compared.
Method: Used a c program for doing it (xytest_cprog). The simulation input file was used (5 frames). The result from pipeline run was extracted for these 5 frames using fv (xyres). Test results are given below.
Expressions used in calculation of x,y:
c1=x/y;
c2=((2* 1024 - x) /y) -1;
s = minimum( 1024/c1, 1024/c2) -1;
w=c1*s;
z=c2*s;
x_eqn = 2048*w/(w+s+z);
y_eqn = 2048*s/(w+s+z);
The same expressions have been used in the java code for w,s,z and x,y calculation.
Result:The x,y values in the fits files (from level1b onwards) are not exactly same as those given as input. There is error of 1 pixel in some events. This may be the round off error, still it may cause loss of accuracy.
Comparison of x,y calculation: indices in x_sim and x_fits are different, since T1 gets 1st event, 4th ,7th .... The events for Telescope 1 have been considered here. The x_eqn and y_eqn are obtained by calculation using the expressions given above.
x_sim[0] =438, y_sim[0] =311 :: x_eqn[0]=438,y_eqn[0]=311 x_fits[0] =438, y_fits[0]=311
x_sim[3] =437, y_sim[3] =313 :: x_eqn[3]=437,y_eqn[3]=313 :::::: Difference x_fits[1] =436, y_fits[1]=313
x_sim[6] =436, y_sim[6] =313 :: x_eqn[6]=436,y_eqn[6]=313 x_fits[2] =436, y_fits[2]=313
x_sim[9] =436, y_sim[9] =314 :: x_eqn[9]=436,y_eqn[9]=314 x_fits[3] =436, y_fits[3]=314
x_sim[12] =437, y_sim[12] =315 :: x_eqn[12]=437,y_eqn[12]=315 x_fits[4] =437, y_fits[4]=315
x_sim[15] =436, y_sim[15] =314 :: x_eqn[15]=436,y_eqn[15]=314 x_fits[5] =436, y_fits[5]=314
x_sim[18] =438, y_sim[18] =313 :: x_eqn[18]=438,y_eqn[18]=313 :::::: Difference x_fits[6] =438, y_fits[6]=312
x_sim[21] =439, y_sim[21] =313 :: x_eqn[21]=439,y_eqn[21]=313 :::::: Difference x_fits[7] =438, y_fits[7]=313
x_sim[24] =436, y_sim[24] =315 :: x_eqn[24]=436,y_eqn[24]=315 x_fits[8] =436, y_fits[8]=315
x_sim[27] =437, y_sim[27] =314 :: x_eqn[27]=437,y_eqn[27]=314 x_fits[9] =437, y_fits[9]=314
x_sim[30] =434, y_sim[30] =311 :: x_eqn[30]=434,y_eqn[30]=311 :::::: Difference x_fits[10] =434, y_fits[10]=310
x_sim[33] =435, y_sim[33] =314 :: x_eqn[33]=435,y_eqn[33]=314 :::::: Difference x_fits[11] =434, y_fits[11]=314
x_sim[36] =437, y_sim[36] =313 :: x_eqn[36]=437,y_eqn[36]=313 :::::: Difference x_fits[12] =436, y_fits[12]=313
x_sim[39] =434, y_sim[39] =315 :: x_eqn[39]=434,y_eqn[39]=315 x_fits[13] =434, y_fits[13]=315
x_sim[42] =437, y_sim[42] =313 :: x_eqn[42]=437,y_eqn[42]=313 :::::: Difference x_fits[14] =436, y_fits[14]=313
x_sim[45] =436, y_sim[45] =312 :: x_eqn[45]=436,y_eqn[45]=312 :::::: Difference x_fits[15] =435, y_fits[15]=312
x_sim[48] =437, y_sim[48] =310 :: x_eqn[48]=437,y_eqn[48]=310 :::::: Difference x_fits[16] =437, y_fits[16]=309
x_sim[51] =433, y_sim[51] =314 :: x_eqn[51]=433,y_eqn[51]=314 x_fits[17] =433, y_fits[17]=314
x_sim[54] =434, y_sim[54] =314 :: x_eqn[54]=434,y_eqn[54]=314 :::::: Difference x_fits[18] =433, y_fits[18]=314
x_sim[57] =434, y_sim[57] =313 :: x_eqn[57]=434,y_eqn[57]=313 x_fits[19] =434, y_fits[19]=313
x_sim[60] =436, y_sim[60] =313 :: x_eqn[60]=436,y_eqn[60]=313 x_fits[20] =436, y_fits[20]=313
x_sim[63] =437, y_sim[63] =310 :: x_eqn[63]=437,y_eqn[63]=310 :::::: Difference x_fits[21] =437, y_fits[21]=309
x_sim[66] =436, y_sim[66] =315 :: x_eqn[66]=436,y_eqn[66]=315 x_fits[22] =436, y_fits[22]=315
x_sim[69] =434, y_sim[69] =312 :: x_eqn[69]=434,y_eqn[69]=312 x_fits[23] =434, y_fits[23]=312
x_sim[72] =435, y_sim[72] =312 :: x_eqn[72]=435,y_eqn[72]=312 :::::: Difference x_fits[24] =435, y_fits[24]=311
x_sim[75] =437, y_sim[75] =313 :: x_eqn[75]=437,y_eqn[75]=313 :::::: Difference x_fits[25] =436, y_fits[25]=313
x_sim[78] =436, y_sim[78] =313 :: x_eqn[78]=436,y_eqn[78]=313 x_fits[26] =436, y_fits[26]=313
x_sim[81] =437, y_sim[81] =313 :: x_eqn[81]=437,y_eqn[81]=313 :::::: Difference x_fits[27] =436, y_fits[27]=313
x_sim[84] =435, y_sim[84] =312 :: x_eqn[84]=435,y_eqn[84]=312 :::::: Difference x_fits[28] =435, y_fits[28]=311
