1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
|
#include <iostream>
#include <iomanip>
#include <vector>
#include <algorithm>
#include <cmath>
#include <cstdint>
#include <cstring>
#include <cassert>
static const char *argv0;
void usage() {
std::cerr << "Usage: " << argv0 << " [-h] [-v] [<lowbound> <highbound>] [<nbins>]" << std::endl
<< "Prints a simple histogram of stdin data in your terminal, using" << std::endl
<< "either the given lower and upper bounds, or the minimum and" << std::endl
<< "maximum extracted from the data." << std::endl
<< "The number of bins can also be passed. (If unspecified, defaults" << std::endl
<< "to 10.)" << std::endl
<< "Data on stdin is assumed to be a list of floating-point values." << std::endl
<< std::endl
<< " -v When passed, prints a histogram with vertical bars. This" << std::endl
<< " usually fits more bars on a terminal, but is less informative" << std::endl
<< " since this view omits exact frequency numbers." << std::endl
<< " -h Show this help." << std::endl;
}
double parsefloat(const char *s, const char *errprefix) {
char *endp;
double v = strtod(s, &endp);
if (!s[0] || *endp) {
std::cerr << errprefix << " '" << s << "'" << std::endl;
usage();
exit(1);
}
return v;
}
int64_t parseint(const char *s, const char *errprefix) {
char *endp;
int64_t v = strtoll(s, &endp, 10);
if (!s[0] || *endp) {
std::cerr << errprefix << " '" << s << "'" << std::endl;
usage();
exit(1);
}
return v;
}
int main(int argc, char **argv) {
argv0 = argv[0];
const int64_t BARWIDTH = 80;
const int64_t BARHEIGHT = 24;
bool vertical = false;
double low = 0, high = 1; // will be overwritten either from arguments or from data
bool havebounds;
int64_t nbins = 10;
std::vector<char*> plainargs;
for (int i = 1; i < argc; i++) {
if (strcmp(argv[i], "-v") == 0) {
vertical = true;
} else if (strcmp(argv[i], "-h") == 0) {
usage();
return 0;
} else {
plainargs.push_back(argv[i]);
}
}
switch (plainargs.size()) {
case 0:
havebounds = false;
break;
case 1:
havebounds = false;
nbins = parseint(plainargs[0], "Invalid number");
break;
case 2:
havebounds = true;
low = parsefloat(plainargs[0], "Invalid number");
high = parsefloat(plainargs[1], "Invalid number");
break;
case 3:
havebounds = true;
low = parsefloat(plainargs[0], "Invalid number");
high = parsefloat(plainargs[1], "Invalid number");
nbins = parseint(plainargs[2], "Invalid number");
break;
default:
usage();
return 1;
}
if (nbins < 1) {
std::cerr << "histogram: Invalid number of bins '" << nbins << "'" << std::endl;
usage();
return 1;
}
if (havebounds && high <= low) {
std::cerr << "histogram: high <= low" << std::endl;
usage();
return 1;
}
// Read data and collect low and high bounds, if necessary
std::vector<double> values;
{
double minval = INFINITY, maxval = -INFINITY;
while (true) {
double v;
std::cin >> v;
if (!std::cin) {
// Check whether it was invalid data or EOF that let the read fail
std::cin.clear();
std::string str;
std::cin >> str;
if (std::cin) {
std::cerr << "histogram: Invalid data starting with word '"
<< str << "'" << std::endl;
usage();
return 1;
} else {
// EOF, so we're done
break;
}
}
values.push_back(v);
if (v < minval) minval = v;
if (v > maxval) maxval = v;
}
if (!havebounds) {
low = minval;
high = maxval;
}
}
if (low == high) {
std::cerr << "histogram: Plot range contains only one point: " << low << std::endl;
usage();
return 1;
}
// Collect data in the histogram
std::vector<int64_t> histogram(nbins, 0);
for (double v : values) {
if (v < low || v > high) {
// cerr << "Point " << v << " out of range!" << endl;
continue;
}
int64_t bin = (v - low) / (high - low) * nbins;
if (bin == nbins) bin--;
assert(bin >= 0 && bin < nbins);
histogram[bin]++;
}
// Compute statistics
int64_t maxtally = *std::max_element(histogram.begin(), histogram.end());
if (maxtally == 0) {
std::cerr << "histogram: No data in range" << std::endl;
return 1;
}
// Print histogram
if (vertical) {
for (int y = BARHEIGHT; y >= 1; y--) {
for (size_t i = 0; i < histogram.size(); i++) {
std::cout << " #"[BARHEIGHT * histogram[i] / maxtally >= y];
}
std::cout << std::endl;
}
std::cout << std::left << std::setw(nbins / 2) << low << ' '
<< std::right << std::setw(nbins - nbins / 2 - 1) << high << std::endl;
} else {
char fullbar[BARWIDTH + 1];
memset(fullbar, '#', BARWIDTH);
fullbar[BARWIDTH] = '\0';
char emptybar[BARWIDTH + 1];
memset(emptybar, ' ', BARWIDTH);
emptybar[BARWIDTH] = '\0';
for (size_t i = 0; i < histogram.size(); i++) {
int64_t tally = histogram[i];
double binlow = low + (double)i / nbins * (high - low);
double binhigh = low + (double)(i + 1) / nbins * (high - low);
int64_t width = BARWIDTH * tally / maxtally;
char terminator = ")]"[i == histogram.size() - 1];
std::cout << fullbar + BARWIDTH - width << emptybar + width
<< " [" << std::setw(11) << binlow << " - " << std::setw(11) << binhigh << terminator
<< " [" << tally << "]" << std::endl;
}
}
}
|
