schiff-output.5 (7312B)
1 .\" Copying and distribution of this file, with or without modification, 2 .\" are permitted in any medium without royalty provided the copyright 3 .\" notice and this notice are preserved. This file is offered as-is, 4 .\" without any warranty. 5 .TH SCHIFF-OUTPUT 5 6 .SH NAME 7 schiff\-output \- format of 8 .BR schiff (1) 9 results. 10 .SH DESCRIPTION 11 The output result of the 12 .BR schiff (1) 13 program is a collection of ASCII floating point data. Each set of floating 14 point values are separated by an empty line. The first set is a list of per 15 wavelength cross\-sections. Each line stores the estimated cross\-section for a 16 wavelength submitted by the \fB\-w\fR option of 17 .BR schiff (1). 18 It is formatted as "W E e A a S s P p" with "W" the wavelength in vacuum 19 (expressed in microns), "E", "A" and "S" the estimation of the extinction, 20 absorption and scattering cross\-sections, respectively, in square microns per 21 particle, and "P" the estimated average projected area of the soft particles 22 expressed in square microns per particle. The "e", "a", "s" and "p" values are 23 the standard error of the aforementioned estimations. 24 .PP 25 Following the list of cross\-sections comes the list of phase function 26 descriptors. Each descriptor is a line that gives informations on the 27 [[inverse] cumulative] phase functions. It is formatted as "W theta-l Ws Ws-SE 28 Wc Wc-SE n nangles nangles\-inv" with "W" the wavelength in vacuum (expressed in 29 microns) of the inverse cumulative phase function, "theta-l" the scattering 30 angle in radians from which the phase function was analytically computed, "Ws" 31 and "Wc" the values of the differential cross\-section and its cumulative at 32 "theta-l", "n" the parameter of the model used to analytically evaluate the 33 phase function for large scattering angles (i.e. angles greater than "theta-l"), 34 "nangles" the number of scattering angles (\fB\-a\fR option of 35 .BR schiff (1)) 36 and "nangles\-inv" the number of inverse cumulative phase function values 37 (\fB\-A\fR option of 38 .BR schiff (1)). 39 The "Ws-SE" and "Wc-SE" values are the standard error of the "Ws" and "Wc" 40 estimations, respectively. 41 .PP 42 Then there is the list of phase functions, each stored as a list of lines 43 formatted as "A E SE" where "E" is the expected value of the phase function for 44 the input scattering angle "A" in radians, and "SE" its standard error. The 45 number of scattering angles is controlled by the \fB\-a\fR option of 46 .BR schiff (1). 47 .PP 48 After the phase functions come the cumulative phase functions that follow the 49 format of the phase functions, i.e. each cumulative phase function is a list a 50 lines \- one per scattering angle \- that defines the input scattering angle in 51 radians, followed by the expected value and the standard error of its cumulative 52 phase function. 53 .PP 54 Finally, there is the inverse cumulative phase functions. Each of these 55 functions lists a set of N probabilities in [0, 1] and its corresponding 56 scattering angles in [0, PI]. The number of entries of the inverse cumulative 57 phase functions is controlled by the \fB\-A\fR option of 58 .BR schiff (1). 59 Assuming a set of N angles, the i^th angle (i in [0, N\-1]) is the angle whose 60 probability is i/(N\-1). 61 .PP 62 Note that the cross sections, the phase function descriptors, the phase 63 functions, their cumulative and their inverse cumulative are all sorted in 64 ascending order with respect to their associated wavelength. 65 .SH GRAMMAR 66 The following grammar formally describes the 67 .BR schiff (1) 68 output format. 69 The output values are ASCII data formatted line by line. By convention, in the 70 following grammar the line data are listed between quote marks. The grammar may 71 use new lines for formatting constraints, but data are actually on the same 72 line while a closed quote mark is not defined. 73 .PP 74 .RS 4 75 .nf 76 <schiff\-output> ::= <cross\-sections> 77 EMPTY\-LINE 78 <phase\-function\-descriptor> 79 EMPTY\-LINE 80 <phase\-functions> 81 EMPTY-LINE 82 <cumulative\-phase\-functions> 83 EMPTY\-LINE 84 <inverse\-cumulative\-phase\-functions> 85 EMPTY\-LINE 86 87 \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\- 88 89 <cross\-sections> ::= "WAVELENGTH <extinction> <absorption> 90 <scattering> <area>" 91 [ <cross\-sections> ] 92 93 <extinction> ::= ESTIMATION STANDARD\-ERROR 94 <absorption> ::= ESTIMATION STANDARD\-ERROR 95 <scattering> ::= ESTIMATION STANDARD\-ERROR 96 <area> ::= ESTIMATION STANDARD\-ERROR 97 98 \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\- 99 100 <phase\-functions\-descriptors> 101 ::= "WAVELENGTH THETA <PF(THETA)> <CDF(THETA)> 102 N #ANGLES #INVCUM" 103 [ <phase\-functions\-descriptors> ] 104 105 <CDF(THETA)> ::= ESTIMATION STANDARD\-ERROR 106 <PF(THETA)> ::= ESTIMATION STANDARD\-ERROR 107 108 \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\- 109 110 <phase\-functions> ::= <function\-entries> 111 [ EMPTY-LINE 112 <phase\-functions> ] 113 114 <cumulative\-phase\-functions> 115 ::= <function\-entries> 116 [ EMPTY-LINE 117 <cumulative\-phase\-functions> ] 118 119 <function\-entries> ::= ANGLE ESTIMATION STANDARD-ERROR 120 [ <phase\-function\-entries> ] 121 122 <inverse\-cumulative\-phase\-functions> 123 ::= <inverse\-function\-entries> 124 [ EMPTY-LINE 125 <inverse\-cumulative\-phase\-functions> ] 126 127 <inverse\-function\-entries> 128 ::= PROBABILITY ANGLE 129 [ <inverse\-function\-entries> ] 130 .fi 131 .SH EXAMPLE 132 The following output is emitted by the 133 .BR schiff (1) 134 program invoked on the wavelengths 0.3 and 0.6 micron. 135 Note that actually, 136 .BR schiff (1) 137 does not write comments, i.e. text preceeded by the "#" character. However 138 comments are added in order to help in understanding the data layout. 139 .RS 4 140 .PP 141 .nf 142 0.3 10.61 0.20 9.51e-3 2.37e-4 10.6 0.20 5.25 0.10 \fB# X\-sections\fR 143 0.6 11.15 0.25 4.76e-3 1.19e-4 11.1 0.25 5.25 0.10 \fB# X\-sections\fR 144 0.3 0.18 1.37 17.6 7.74 0.73 0.80 1000 2000 \fB# descriptor\fR 145 0.6 0.26 9.81 5.26 7.65 0.48 2.90 1000 2000 \fB# descriptor\fR 146 0 520.23 64.2971 \fB# Phase function (0.3 micron)\fR 147 0.00314474 474.315 50.6471 148 ... 149 3.13845 0.0196258 0 150 3.14159 0.0196259 0 151 .PP 152 0 150.183 25.4822 \fB# Phase function (0.6 micron)\fR 153 0.00314474 145.969 23.7955 154 ... 155 3.13845 0.00262338 0 156 3.14159 0.00262338 0 157 .PP 158 0 0 0 \fB# Cumulative (0.3 micron)\fR 159 0.00314474 0.0154297 0.00177366 160 ... 161 3.13845 0.999999 0 162 3.14159 1 0 163 .PP 164 0 0 0 \fB# Cumulative (0.6 micron)\fR 165 0.00314474 0.00460001 0.000765182 166 ... 167 3.13845 1 0 168 3.14159 1 0 169 .PP 170 0 0 \fB# Inverse cumulative (0.3 micron)\fR 171 0.00050025 0.000101956 172 ... 173 0.9995 3.05143 174 1 3.14159 175 .PP 176 0 0 \fB# Inverse cumulative (0.6 micron)\fR 177 0.00050025 0.00034199 178 ... 179 0.9995 2.89409 180 1 3.14159 181 .fi 182 .SH SEE ALSO 183 .BR schiff (1)