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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278
/// Assert that two numbers are almost equal to each other.
///
/// On panic, this macro will print the values of the expressions with their
/// debug representations.
#[macro_export]
macro_rules! assert_almost_eq {
($a:expr, $b:expr, $prec:expr) => {
let diff = ($a - $b).abs();
if diff > $prec {
panic!(
"assertion failed: `abs(left - right) = {:.1e} < {:e}`, \
(left: `{}`, right: `{}`)",
diff, $prec, $a, $b
);
}
};
}
/// Concatenate several iterative estimators into one.
///
/// `$name` is the name of the new struct. `$statistic` is the name of a
/// statistic and must exist as a method of the corresponding type `$estimator`.
/// `$estimator` must have an `add` method for adding new observations to the
/// sample (taking an `f64` as an argument). It must also implement `Default`.
///
/// If the short syntax is used, the fields will be named `$statistic`. Use the
/// long syntax and `$field` to give them explicit names. The long syntax also
/// supports calculating several statistics from one estimator.
///
/// For moments, only an estimator for the highest moment should be used and
/// reused for the lower moments (see the example below).
///
/// The following methods will be implemented: `new`, `add`, `$statistic`.
///
/// The following traits will be implemented: `Default`, `FromIterator<f64>`.
///
///
/// # Examples
///
/// ```
/// use average::{Min, Max, Estimate, concatenate};
///
/// concatenate!(MinMax, [Min, min], [Max, max]);
///
/// let s: MinMax = (1..6).map(f64::from).collect();
///
/// assert_eq!(s.min(), 1.0);
/// assert_eq!(s.max(), 5.0);
/// ```
///
/// The generated code looks roughly like this:
///
/// ```
/// # use average::{Min, Max, Estimate};
/// #
/// struct MinMax {
/// min: Min,
/// max: Max,
/// }
///
/// impl MinMax {
/// pub fn new() -> MinMax {
/// MinMax { min: Min::default(), max: Max::default() }
/// }
///
/// pub fn add(&mut self, x: f64) {
/// self.min.add(x);
/// self.max.add(x);
/// }
///
/// pub fn min(&self) -> f64 {
/// self.min.min()
/// }
///
/// pub fn max(&self) -> f64 {
/// self.max.max()
/// }
/// }
/// ```
///
/// If you want to calculate the mean, variance and the median in one pass, you
/// can do the following:
///
/// ```ignore
/// use average::{Variance, Quantile, Estimate, concatenate};
///
/// concatenate!(Estimator,
/// [Variance, variance, mean, sample_variance],
/// [Quantile, quantile, quantile]);
/// ```
#[macro_export]
macro_rules! concatenate {
( $visibility:vis $name:ident, $([$estimator:ident, $statistic:ident]),+ ) => {
concatenate!($visibility $name, $([$estimator, $statistic, $statistic]),* );
};
( $visibility:vis $name:ident, $( [$estimator:ident, $field:ident, $($statistic:ident),+] ),+ ) => {
$visibility struct $name {
$(
$field: $estimator,
)*
}
impl $name {
#[inline]
pub fn new() -> $name {
$name {
$(
$field: ::core::default::Default::default(),
)*
}
}
#[inline]
pub fn add(&mut self, x: f64) {
$(
self.$field.add(x);
)*
}
$( $(
#[inline]
pub fn $statistic(&self) -> f64 {
self.$field.$statistic()
}
)* )*
}
impl Default for $name {
fn default() -> $name {
$name::new()
}
}
$crate::impl_from_iterator!($name);
// This should be conditionally activated if all fields implement `Merge`.
// Could probably be implemented with specialization.
/*
impl $crate::Merge for $name {
#[inline]
fn merge(&mut self, other: &Self) {
use $crate::Merge;
$(
self.$field.merge(&other.$field);
)*
}
}
*/
};
}
/// Implement `FromIterator<f64>` for an iterative estimator.
#[macro_export]
macro_rules! impl_from_iterator {
( $name:ident ) => {
impl ::core::iter::FromIterator<f64> for $name {
fn from_iter<T>(iter: T) -> $name
where
T: IntoIterator<Item = f64>,
{
let mut e = $name::new();
for i in iter {
e.add(i);
}
e
}
}
impl<'a> ::core::iter::FromIterator<&'a f64> for $name {
fn from_iter<T>(iter: T) -> $name
where
T: IntoIterator<Item = &'a f64>,
{
let mut e = $name::new();
for &i in iter {
e.add(i);
}
e
}
}
};
}
/// Implement `FromParallelIterator<f64>` for an iterative estimator.
///
/// This will do nothing unless the `rayon` feature is enabled.
#[macro_export]
macro_rules! impl_from_par_iterator {
( $name:ident ) => {
#[cfg(feature = "rayon")]
#[cfg_attr(doc_cfg, doc(cfg(feature = "rayon")))]
impl ::rayon::iter::FromParallelIterator<f64> for $name {
fn from_par_iter<I>(par_iter: I) -> $name
where
I: ::rayon::iter::IntoParallelIterator<Item = f64>,
Self: $crate::Merge,
{
use ::rayon::iter::ParallelIterator;
use $crate::Merge;
let par_iter = par_iter.into_par_iter();
par_iter
.fold(
|| $name::new(),
|mut e, i| {
e.add(i);
e
},
)
.reduce(
|| $name::new(),
|mut a, b| {
a.merge(&b);
a
},
)
}
}
#[cfg(feature = "rayon")]
#[cfg_attr(doc_cfg, doc(cfg(feature = "rayon")))]
impl<'a> ::rayon::iter::FromParallelIterator<&'a f64> for $name {
fn from_par_iter<I>(par_iter: I) -> $name
where
I: ::rayon::iter::IntoParallelIterator<Item = &'a f64>,
Self: $crate::Merge,
{
use ::rayon::iter::ParallelIterator;
use $crate::Merge;
let par_iter = par_iter.into_par_iter();
par_iter
.fold(
|| $name::new(),
|mut e, i| {
e.add(*i);
e
},
)
.reduce(
|| $name::new(),
|mut a, b| {
a.merge(&b);
a
},
)
}
}
};
}
/// Implement `Extend<f64>` for an iterative estimator.
#[macro_export]
macro_rules! impl_extend {
( $name:ident ) => {
impl ::core::iter::Extend<f64> for $name {
fn extend<T>(&mut self, iter: T)
where
T: IntoIterator<Item = f64>,
{
for i in iter {
self.add(i);
}
}
}
impl<'a> ::core::iter::Extend<&'a f64> for $name {
fn extend<T>(&mut self, iter: T)
where
T: IntoIterator<Item = &'a f64>,
{
for &i in iter {
self.add(i);
}
}
}
};
}