GEO 384S HW0.

book/geo384s/hw0/Mnonlocal.c

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+/* Non-local smoothing. */
+#include <rsf.h>
+
+int main (int argc, char *argv[])
+{
+    int n1,n2, i1,i2, is, ns;
+    float *trace, *trace2, ax, ay, t;
+    sf_file inp, out;
+
+    /* initialize */
+    sf_init(argc,argv);
+
+    /* set input and output files */
+    inp = sf_input("in");
+    out = sf_output("out");
+
+    /* get input dimensions */
+    if (!sf_histint(inp,"n1",&n1)) 
+	sf_error("No n1= in input");
+    n2 = sf_leftsize(inp,1);
+
+    /* get command-line parameters */
+    if (!sf_getint("ns",&ns)) sf_error("Need ns=");
+    /* spray radius */
+
+    if (!sf_getfloat("ax",&ax)) sf_error("Need ax=");
+    /* exponential weight for the coordinate distance */
+
+    trace = sf_floatalloc(n1);
+    trace2 = sf_floatalloc(n1);
+
+    /* loop over traces */
+    for (i2=0; i2 < n2; i2++) {
+	/* read input */
+	sf_floatread(trace,n1,inp);
+
+	/* loop over samples */
+	for (i1=0; i1 < n1; i1++) {	    
+	    t = 0.;
+
+	    /* accumulate shifts */
+	    for (is=-ns; is <= ns; is++) {
+		if (i1+is >= 0 && i1+is < n1) {
+
+		    /* !!!MODIFY THE NEXT LINE!!! */
+		    t += trace[i1+is]*expf(-ax*is*is);
+		} 
+	    }
+
+	    trace2[i1] = t;
+	}
+
+	/* write output */
+	sf_floatwrite(trace2,n1,out);
+    }
+
+    /* clean up */
+    sf_fileclose(inp);
+    exit (0);
+}
+
+

book/geo384s/hw0/SConstruct

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+from rsf.tex import *
+
+End(use='hyperref,listings',options='reproduce',
+    color='horizon smoothed mona smoothed2',
+    include=r'''
+\newlength{\boxwidth}
+\setlength{\boxwidth}{\textwidth}
+\addtolength{\boxwidth}{-50pt} 
+\setlength{\fboxsep}{10pt}
+\newcommand{\answer}[1]{\noindent\fbox{\parbox{\boxwidth}{\textbf{Answer:} #1}}}
+    ''')

book/geo384s/hw0/channel/SConstruct

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+from rsf.proj import *
+
+# Download data
+Fetch('horizon.asc','hall')
+
+# Convert format
+Flow('horizon','horizon.asc',
+     '''
+     echo in=$SOURCE data_format=ascii_float n1=3 n2=57036 | 
+     dd form=native | window n1=1 f1=-1 |
+     put
+     n1=196 o1=33.139 d1=0.01 label1=y unit1=km
+     n2=291 o2=35.031 d2=0.01 label2=x unit2=km 
+     ''')
+
+# Triangle smoothing
+Flow('smoothed','horizon','smooth rect1=20 rect2=20')
+
+# Display results
+for horizon in ('horizon','smoothed'):
+    # --- CHANGE BELOW ---
+    Plot(horizon,'grey color=j bias=65 yreverse=n wanttitle=n')
+    edge = 'edge-'+horizon
+    Flow(edge,horizon,'canny max=98 | dd type=float')
+    Plot(edge,'grey allpos=y yreverse=n wanttitle=n')
+    Result(horizon,[horizon,edge],'SideBySideIso')
+
+End()

book/geo384s/hw0/channel2/SConstruct

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+from rsf.proj import *
+
+# Download data
+Fetch('horizon.asc','hall')
+
+# Convert format
+Flow('horizon2','horizon.asc',
+     '''
+     echo in=$SOURCE data_format=ascii_float n1=3 n2=57036 | 
+     dd form=native | window n1=1 f1=-1 |
+     add add=-65 | put
+     n1=196 o1=33.139 d1=0.01 label1=y unit1=km
+     n2=291 o2=35.031 d2=0.01 label2=x unit2=km 
+     ''',stdin=0)
+Result('horizon2','grey  yreverse=n color=j title=Input')
+
+# Spray
+Flow('spray','horizon2',
+     '''
+     spray axis=3 n=21 o=-0.1 d=0.01 |
+     spray axis=4 n=21 o=-0.1 d=0.01
+     ''')
+
+# Shift
+Flow('shift1','spray','window n1=1 | math output=x2')
+Flow('shift2','spray','window n2=1 | math output=x3')
+
+Flow('local','spray shift1 shift2',
+     '''
+     datstretch datum=${SOURCES[1]} | transp |
+     datstretch datum=${SOURCES[2]} | transp
+     ''')
+Plot('local','window j3=4 j4=4 | grey color=j',view=1)
+
+# --- CHANGE BELOW ---
+# try "exp(-0.1*(input-loc)^2-200*(x3^2+x4^2))"
+Flow('simil','spray local',
+     '''
+     math loc=${SOURCES[1]} output=1 
+     ''')
+
+Flow('norm','simil',
+     'stack axis=4 | stack axis=3')
+
+Flow('smoothed2','local simil norm',
+     '''
+     add mode=p ${SOURCES[1]} |
+     stack axis=4 | stack axis=3 |
+     add mode=d ${SOURCES[2]}
+     ''')
+Result('smoothed2','grey yreverse=n color=j title=Output')
+
+End()

book/geo384s/hw0/local/SConstruct

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+from rsf.proj import *
+
+# Generate synthetic data
+Flow('step',None,
+     '''
+     spike nsp=3 n1=101 k1=26,51,76 mag=-1,2,-1 d1=1 label1= unit1= |
+     causint |
+     noise seed=62009 var=0.001
+     ''')
+Result('step','dots')
+
+# Conventional smoothing
+Flow('smooth','step','smooth rect1=10')
+Result('smooth','dots')
+
+# Spray by repeating the input
+Flow('spray','step','spray axis=2 d=1 o=-10 n=21')
+Result('spray','dots')
+
+# Shift each trace
+Flow('shift','spray','window n1=1 | math output=x1')
+Flow('local','spray shift',
+     'datstretch datum=${SOURCES[1]}')
+Result('local','dots')
+
+# Triangle weight
+# --- CHANGE BELOW ---
+Flow('triangle','local','math output="1-abs(x2)/10" ')
+Flow('tnorm','triangle','stack')
+Result('triangle','dots gaineach=n title="Triangle Weight" ')
+
+# Triangle smoothing by weighting and stacking
+Flow('smooth2','local triangle tnorm',
+     '''
+     add mode=p ${SOURCES[1]} |
+     stack |
+     add mode=d ${SOURCES[2]}
+     ''')
+Result('smooth2','dots title="Triangle Smoothing 2" title=')
+
+# Nonlocal weight
+Flow('similarity','spray local triangle',
+     '''math loc=${SOURCES[1]} tri=${SOURCES[2]}
+     output="tri*exp(-10*(input-loc)^2)"''')
+Result('similarity','dots gaineach=n title="Similarity Weight" ')
+
+# Multiply two weights together
+Flow('nlnorm','similarity','stack')
+Flow('nlsmooth','local similarity nlnorm',
+     '''
+     add mode=p ${SOURCES[1]} |
+     stack |
+     add mode=d ${SOURCES[2]}
+     ''')
+Result('nlsmooth','dots')
+
+End()

book/geo384s/hw0/mona/SConstruct

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+from rsf.proj import *
+
+# Download data
+Fetch('mona.img','imgs')
+
+# Convert to standard format
+Flow('mona','mona.img',
+     '''
+     echo n1=512 n2=513 in=$SOURCE data_format=native_uchar |
+     dd type=float
+     ''',stdin=0)
+
+Result('mona',
+       '''
+       grey transp=n allpos=y title="Mona Lisa"
+       color=b screenratio=1 wantaxis=n
+       ''')
+
+End()