Modulus provides several general and domain-specific metric calculations you can leverage in your custom training and inference workflows. These metrics are optimized to operate on PyTorch tensors.
General Metrics and Statistical Methods
Below is a summary of general purpose statistical methods and metrics that are available:
Metric |
Description |
---|---|
modulus.metrics.general.mse.mse | Mean Squared error between two tensors |
modulus.metrics.general.mse.rmse | Root Mean Squared error between two tensors |
modulus.metrics.general.histogram.histogram | Histogram of a set of tensors over the leading dimension |
modulus.metrics.general.histogram.cdf | Cumulative density function of a set of tensors over the leading dimension |
modulus.metrics.general.histogram.normal_cdf | Cumulative density function of a normal variable with given mean and standard deviation |
modulus.metrics.general.histogram.normal_pdf | Probability density function of a normal variable with given mean and standard deviation |
modulus.metrics.general.calibration.find_rank | Find the rank of the observation with respect to the given counts and bins |
modulus.metrics.general.calibration.rank_probability_score | Rank Probability Score for the passed ranks |
modulus.metrics.general.entropy.entropy_from_counts | Computes the statistical entropy of a random variable using a histogram. |
modulus.metrics.general.entropy.relative_entropy_from_counts | Computes the relative statistical entropy, or KL Divergence of two random variables using their histograms. |
modulus.metrics.general.crps.crps | Local Continuous Ranked Probability Score (CRPS) by computing a histogram and CDF of the predictions |
modulus.metrics.general.wasserstein.wasserstein | 1-Wasserstein distance between two discrete CDF functions |
modulus.metrics.general.reduction.WeightedMean | Weighted Mean |
modulus.metrics.general.reduction.WeightedStatistic | Weighted Statistic |
modulus.metrics.general.reduction.WeightedVariance | Weighted Variance |
Below shows some examples of how to use these metrics in your own workflows.
To compute RMSE metric:
>>> import torch
>>> from modulus.metrics.general.mse import rmse
>>> pred_tensor = torch.randn(16, 32)
>>> targ_tensor = torch.randn(16, 32)
>>> rmse(pred_tensor, targ_tensor)
tensor(1.4781)
To compute the histogram of samples:
>>> import torch
>>> from modulus.metrics.general import histogram
>>> x = torch.randn(1_000)
>>> bins, counts = histogram.histogram(x, bins = 10)
>>> bins
tensor([-3.7709, -3.0633, -2.3556, -1.6479, -0.9403, -0.2326, 0.4751, 1.1827,
1.8904, 2.5980, 3.3057])
>>> counts
tensor([ 3, 9, 43, 150, 227, 254, 206, 81, 24, 3])
To use compute the continuous density function (CDF):
>>> bins, cdf = histogram.cdf(x, bins = 10)
>>> bins
tensor([-3.7709, -3.0633, -2.3556, -1.6479, -0.9403, -0.2326, 0.4751, 1.1827,
1.8904, 2.5980, 3.3057])
>>> cdf
tensor([0.0030, 0.0120, 0.0550, 0.2050, 0.4320, 0.6860, 0.8920, 0.9730, 0.9970,
1.0000])
To use the histogram for statistical entropy calculations:
>> from modulus.metrics.general import entropy
>>> entropy.entropy_from_counts(counts, bins)
tensor(0.4146)
Many of the functions operate over batches. For example, if one has a collection of two dimensional data, then we can compute the histogram over the collection:
>>> import torch
>>> from modulus.metrics.general import histogram, entropy
>>> x = torch.randn((1_000, 3, 3))
>>> bins, counts = histogram.histogram(x, bins = 10)
>>> bins.shape, counts.shape
(torch.Size([11, 3, 3]), torch.Size([10, 3, 3]))
>>> entropy.entropy_from_counts(counts, bins)
tensor([[0.5162, 0.4821, 0.3976],
[0.5099, 0.5309, 0.4519],
[0.4580, 0.4290, 0.5121]])
There are additional metrics to compute differences between distributions: Ranks, Continuous Rank Probability Skill, and Wasserstein metric.
CRPS:
>>> from modulus.metrics.general import crps
>>> x = torch.randn((1_000,1))
>>> y = torch.randn((1,))
>>> crps.crps(x, y)
tensor([0.8023])
Ranks:
>>> from modulus.metrics.general import histogram, calibration
>>> x = torch.randn((1_000,1))
>>> y = torch.randn((1,))
>>> bins, counts = histogram.histogram(x, bins = 10)
>>> ranks = calibration.find_rank(bins, counts, y)
tensor([0.1920])
Wasserstein Metric:
>>> from modulus.metrics.general import wasserstein, histogram
>>> x = torch.randn((1_000,1))
>>> y = torch.randn((1_000,1))
>>> bins, cdf_x = histogram.cdf(x)
>>> bins, cdf_y = histogram.cdf(y, bins = bins)
>>> wasserstein(bins, cdf_x, cdf_y)
>>> wasserstein.wasserstein(bins, cdf_x, cdf_y)
tensor([0.0459])
Weighted Reductions
Modulus currently offers classes for weighted mean and variance reductions.
>>> from modulus.metrics.general import reduction
>>> x = torch.randn((1_000,))
>>> weights = torch.cos(torch.linspace(-torch.pi/4, torch.pi/4, 1_000))
>>> wm = reduction.WeightedMean(weights)
>>> wm(x, dim = 0)
tensor(0.0365)
>>> wv = reduction.WeightedVariance(weights)
>>> wv(x, dim = 0)
tensor(1.0148)
Online Statistical Methods
Modulus current offers routines for computing online, or out-of-memory, means, variances, and histograms.
>>> import torch
>>> from modulus.metrics.general import ensemble_metrics as em
>>> x = torch.randn((1_000, 2)) # Interpret as 1_000 members of size (2,).
>>> torch.mean(x, dim = 0) # Compute mean of entire data.
tensor([-0.0545, 0.0267])
>>> x0, x1 = x[:500], x[500:] # Split data into two.
>>> M = em.Mean(input_shape = (2,)) # Must pass shape of data
>>> M(x0) # Compute mean of initial batch.
tensor([-0.0722, 0.0414])
>>> M.update(x1) # Update with second batch.
tensor([-0.0545, 0.0267])
Climate Related Metrics
To compute the Anomaly Correlation Coefficient, a metric widely used in weather and climate sciences:
>>> import torch
>>> import numpy as np
>>> from modulus.metrics.climate.acc import acc
>>> channels = 1
>>> img_shape = (32, 64)
>>> time_means = np.pi / 2 * np.ones((channels, img_shape[0], img_shape[1]), dtype=np.float32)
>>> x = np.linspace(-180, 180, img_shape[1], dtype=np.float32)
>>> y = np.linspace(-90, 90, img_shape[0], dtype=np.float32)
>>> xv, yv = np.meshgrid(x, y)
>>> pred_tensor_np = np.cos(2 * np.pi * yv / (180))
>>> targ_tensor_np = np.cos(np.pi * yv / (180))
>>> pred_tensor = torch.from_numpy(pred_tensor_np).expand(channels, -1, -1)
>>> targ_tensor = torch.from_numpy(targ_tensor_np).expand(channels, -1, -1)
>>> means_tensor = torch.from_numpy(time_means)
>>> lat = torch.from_numpy(y)
>>> acc(pred_tensor, targ_tensor, means_tensor, lat)
tensor([0.9841])
- modulus.metrics.general.mse.mse(pred: Tensor, target: Tensor, dim: Optional[int] = None) → Union[Tensor, float][source]
Calculates Mean Squared error between two tensors
- Parameters
pred (Tensor) – Input prediction tensor
target (Tensor) – Target tensor
dim (int, optional) – Reduction dimension. When None the losses are averaged or summed over all observations, by default None
- Returns
- Return type
Mean squared error value(s)
Union[Tensor, float]
- modulus.metrics.general.mse.rmse(pred: Tensor, target: Tensor, dim: Optional[int] = None) → Union[Tensor, float][source]
Calculates Root mean Squared error between two tensors
- Parameters
pred (Tensor) – Input prediction tensor
target (Tensor) – Target tensor
dim (int, optional) – Reduction dimension. When None the losses are averaged or summed over all observations, by default None
- Returns
- Return type
Root mean squared error value(s)
Union[Tensor, float]
- class modulus.metrics.general.histogram.Histogram(input_shape: Tuple[int], bins: Union[int, Tensor] = 10, tol: float = 0.01, **kwargs)[source]
Bases:
EnsembleMetrics
Convenience class for computing histograms, possibly as a part of a distributed or iterative environment
- Parameters
input_shape (Tuple[int]) – Input data shape
bins (Union[int, Tensor], optional) – Initial bin edges or number of bins to use, by default 10
tol (float, optional) – Bin edge tolerance, by default 1e-3
- finalize(cdf: bool = False) → Tuple[Tensor, Tensor][source]
Finalize the histogram, which computes the pdf and cdf
- Parameters
- Returns
- Return type
cdf (bool, optional) – Compute a cumulative density function; will calculate probability density function otherwise, by default False
The calculated (bin edges [N+1, …], PDF or CDF [N, …]) tensors
Tuple[Tensor, Tensor]
- update(input: Tensor) → Tuple[Tensor, Tensor][source]
Update current histogram with new data
- Parameters
- Returns
- Return type
inputs (Tensor) – Input data tensor [B, …]
The calculated (bin edges [N+1, …], counts [N, …]) tensors
Tuple[Tensor, Tensor]
- modulus.metrics.general.histogram.cdf(*inputs: Tensor, bins: Union[int, Tensor] = 10, counts: Union[None, Tensor] = None, verbose: bool = False) → Tuple[Tensor, Tensor][source]
Computes the cumulative density function of a set of tensors over the leading dimension
This function will compute CDF bins of given input tensors. If existing bins or count tensors are supplied, this function will update these existing statistics with the new data.
- Parameters
inputs ((Tensor ...)) – Input data tensor(s) [B, …]
bins (Union[int, Tensor], optional) – Either the number of bins, or a tensor of bin edges with dimension [N+1, …] where N is the number of bins. If counts is passed, then bins is interpreted to be the bin edges for the counts tensor, by default 10
counts (Union[None, Tensor], optional) – Existing count tensor to combine results with. Must have dimensions [N, …] where N is the number of bins. Passing a tensor may also require recomputing the passed bins to make sure inputs and bins are compatible, by default None
verbose (bool, optional) – Verbose printing, by default False
- Returns
- Return type
The calculated (bin edges [N+1, …], cdf [N, …]) tensors
Tuple[Tensor, Tensor]
- modulus.metrics.general.histogram.histogram(*inputs: Tensor, bins: Union[int, Tensor] = 10, counts: Union[None, Tensor] = None, verbose: bool = False) → Tuple[Tensor, Tensor][source]
Computes the histogram of a set of tensors over the leading dimension
This function will compute bin edges and bin counts of given input tensors. If existing bin edges or count tensors are supplied, this function will update these existing statistics with the new data.
- Parameters
inputs ((Tensor ...)) – Input data tensor(s) [B, …]
bins (Union[int, Tensor], optional) – Either the number of bins, or a tensor of bin edges with dimension [N+1, …] where N is the number of bins. If counts is passed, then bins is interpreted to be the bin edges for the counts tensor, by default 10
counts (Union[None, Tensor], optional) – Existing count tensor to combine results with. Must have dimensions [N, …] where N is the number of bins. Passing a tensor may also require recomputing the passed bins to make sure inputs and bins are compatible, by default None
verbose (bool, optional) – Verbose printing, by default False
- Returns
- Return type
The calculated (bin edges [N+1, …], count [N, …]) tensors
Tuple[Tensor, Tensor]
- modulus.metrics.general.histogram.normal_cdf(mean: Tensor, std: Tensor, bin_edges: Tensor, grid: str = 'midpoint') → Tensor[source]
Computes the cumulative density function of a normal variable with given mean and standard deviation. This CDF is given at the locations given by the midpoint of the bin_edges.
This function uses the standard formula:
(1)\[\frac{1}{2} ( 1 + erf( \frac{x-mean}{std \sqrt{2}}) ) )\]
where erf is the error function.
- Parameters
mean (Tensor) – mean tensor
std (Tensor) – standard deviation tensor
bins (Tensor) – The tensor of bin edges with dimension [N+1, …] where N is the number of bins.
grid (str) – A string that indicates where in the bins should the cdf be defined. Can be one of {“mids”, “left”, “right”}.
- Returns
- Return type
The calculated cdf tensor with dimension [N, …]
Tensor
- modulus.metrics.general.histogram.normal_pdf(mean: Tensor, std: Tensor, bin_edges: Tensor, grid: str = 'midpoint') → Tensor[source]
Computes the probability density function of a normal variable with given mean and standard deviation. This PDF is given at the locations given by the midpoint of the bin_edges.
This function uses the standard formula:
(2)\[\frac{1}{\sqrt{2*\pi} std } \exp( -\frac{1}{2} (\frac{x-mean}{std})^2 )\]
where erf is the error function.
- Parameters
mean (Tensor) – mean tensor
std (Tensor) – standard deviation tensor
bins (Tensor) – The tensor of bin edges with dimension [N+1, …] where N is the number of bins.
grid (str) – A string that indicates where in the bins should the cdf be defined. Can be one of {“midpoint”, “left”, “right”}.
- Returns
- Return type
The calculated cdf tensor with dimension [N, …]
Tensor
- modulus.metrics.general.entropy.entropy_from_counts(p: Tensor, bin_edges: Tensor, normalized=True) → Tensor[source]
Computes the Statistical Entropy of a random variable using a histogram.
Uses the formula:
(3)\[Entropy(X) = \int p(x) * \log( p(x) ) dx\]
- Parameters
p (Tensor) – Tensor [N, …] containing counts/pdf, defined over bins. The non-zeroth dimensions of bin_edges and p must be compatible.
bins_edges (Tensor) – Tensor [N+1, …] containing bin edges. The leading dimension must represent the N+1 bin edges.
normalized (Bool, Optional) – Boolean flag determining whether the returned statistical entropy is normalized. Normally the entropy for a compact bounded probability distribution is bounded between a pseudo-dirac distribution, ent_min, and a uniform distribution, ent_max. This normalization transforms the entropy from [ent_min, ent_max] to [0, 1]
- Returns
- Return type
Tensor containing the Information/Statistical Entropy
Tensor
- modulus.metrics.general.entropy.relative_entropy_from_counts(p: Tensor, q: Tensor, bin_edges: Tensor) → Tensor[source]
Computes the Relative Statistical Entropy, or KL Divergence of two random variables using their histograms.
Uses the formula:
(4)\[Entropy(X) = \int p(x) * \log( p(x)/q(x) ) dx\]
- Parameters
p (Tensor) – Tensor [N, …] containing counts/pdf, defined over bins. The non-zeroth dimensions of bin_edges and p must be compatible.
q (Tensor) – Tensor [N, …] containing counts/pdf, defined over bins. The non-zeroth dimensions of bin_edges and q must be compatible.
bins_edges (Tensor) – Tensor [N+1, …] containing bin edges. The leading dimension must represent the N+1 bin edges.
- Returns
- Return type
Map of Statistical Entropy
Tensor
- modulus.metrics.general.calibration.find_rank(bin_edges: Tensor, counts: Tensor, obs: Union[Tensor, ndarray]) → Tensor[source]
Finds the rank of the observation with respect to the given counts and bins.
- Parameters
bins_edges (Tensor) – Tensor [N+1, …] containing bin edges. The leading dimension must represent the N+1 bin edges.
counts (Tensor) – Tensor [N, …] containing counts, defined over bins. The non-zeroth dimensions of bins and counts must be compatible.
obs (Union[Tensor, np.ndarray]) – Tensor or array containing an observation over which the ranks is computed with respect to.
- Returns
- Return type
Tensor of rank for eac of the batched dimensions […]
Tensor
- modulus.metrics.general.calibration.rank_probability_score(ranks: Tensor) → Tensor[source]
Computes the Rank Probability Score for the passed ranks. Internally, this creates a histogram for the ranks and computes the Rank Probability Score (RPS) using the histogram.
With the histogram the RPS is computed as
(5)\[\int_0^1 (F_X(x) - F_U(x))^2 dx\]
where F represents a cumulative distribution function, X represents the rank distribution and U represents a Uniform distribution.
For computation of the ranks, use _find_rank.
- Parameters
- Returns
- Return type
ranks (Tensor) – Tensor [B, …] containing ranks, where the leading dimension represents the batch, or ensemble, dimension. The non-zeroth dimensions are batched over.
Tensor of RPS for each of the batched dimensions […]
Tensor
- modulus.metrics.general.crps.crps(pred: Tensor, obs: Union[Tensor, ndarray], dim: int = 0, method: str = 'kernel') → Tensor[source]
Computes the local Continuous Ranked Probability Score (CRPS) by either computing a histogram and CDF of the predictions, or using the kernel definition.
Creates a map of CRPS and does not accumulate over lat/lon regions.
Computes:
(6)\[CRPS(x, y) = E[X-y] - 0.5*E[X-X'] if B < 100 CRPS(X, y) = int[ (F(x) - 1[x - y])^2 ] dx otherwise\]
where F is the empirical cdf of X.
- Parameters
pred (Tensor) – Tensor containing the ensemble predictions.
obs (Union[Tensor, np.ndarray]) – Tensor or array containing an observation over which the CRPS is computed with respect to.
dim (int, Optional) – Dimension with which to calculate the CRPS over, the ensemble dimension. Assumed to be zero.
method (str, Optional) – The method to calculate the crps. Can either be “kernel” or “histogram”.
- Returns
- Return type
Map of CRPS
Tensor
- class modulus.metrics.general.ensemble_metrics.EnsembleMetrics(input_shape: Union[Tuple[int, ...], List[int]], device: Union[str, device] = 'cpu', dtype: dtype = torch.float32)[source]
Bases:
ABC
Abstract class for ensemble performance related metrics
Can be helpful for distributed and sequential computations of metrics.
- Parameters
input_shape (Union[Tuple[int,...], List]) – Shape of input tensors without batched dimension.
device (torch.device, optional) – Pytorch device model is on, by default ‘cpu’
dtype (torch.dtype, optional) – Standard dtype to initialize any tensor with
- finalize(*args)[source]
Marks the end of the sequential calculation, used to finalize any computations.
- update(*args)[source]
Update initial or stored calculation with additional information.
- class modulus.metrics.general.ensemble_metrics.Mean(input_shape: Union[Tuple, List], **kwargs)[source]
Bases:
EnsembleMetrics
Utility class that computes the mean over a batched or ensemble dimension
This is particularly useful for distributed environments and sequential computation.
- Parameters
input_shape (Union[Tuple, List]) – Shape of broadcasted dimensions
- finalize() → Tensor[source]
Compute and store final mean
- Returns
- Return type
Final mean value
Tensor
- update(inputs: Tensor, dim: int = 0) → Tensor[source]
Update current mean and essential statistics with new data
- Parameters
inputs (Tensor) – Inputs tensor
dim (int) – Dimension of batched data
- Returns
- Return type
Current mean value
Tensor
- class modulus.metrics.general.ensemble_metrics.Variance(input_shape: Union[Tuple, List], **kwargs)[source]
Bases:
EnsembleMetrics
Utility class that computes the variance over a batched or ensemble dimension
This is particularly useful for distributed environments and sequential computation.
- Parameters
input_shape (Union[Tuple, List]) – Shape of broadcasted dimensions
NoteSee “Updating Formulae and a Pairwise Algorithm for Computing Sample Variances” by Chan et al. http://i.stanford.edu/pub/cstr/reports/cs/tr/79/773/CS-TR-79-773.pdf for details.
- finalize(std: bool = False) → Tuple[Tensor, Tensor][source]
Compute and store final mean and unbiased variance / std
- Parameters
- Returns
- Return type
std (bool, optional) – Compute standard deviation, by default False
Final (mean, variance/std) value
Tensor
- property mean: Tensor
Mean value
- update(inputs: Tensor) → Tensor[source]
Update current variance value and essential statistics with new data
- Parameters
- Returns
- Return type
inputs (Tensor) – Input data
Unbiased variance tensor
Tensor
- class modulus.metrics.general.reduction.WeightedMean(weights: Tensor)[source]
Bases:
WeightedStatistic
Compute weighted mean of some input.
- Parameters
weights (Tensor) – Weight tensor
- class modulus.metrics.general.reduction.WeightedStatistic(weights: Tensor)[source]
Bases:
ABC
A convenience class for computing weighted statistics of some input
- Parameters
weights (Tensor) – Weight tensor
- class modulus.metrics.general.reduction.WeightedVariance(weights: Tensor)[source]
Bases:
WeightedStatistic
Compute weighted variance of some input.
- Parameters
weights (Tensor) – Weight tensor
- modulus.metrics.general.wasserstein.wasserstein(bin_edges: Tensor, cdf_x: Tensor, cdf_y: Tensor) → Tensor[source]
1-Wasserstein distance between two discrete CDF functions
This norm is typically used to compare two different forecast ensembles (for X and Y). Creates a map of distance and does not accumulate over lat/lon regions. Computes
(7)\[W(F_X, F_Y) = int[ |F_X(x) - F_Y(x)| ] dx\]
where F_X is the empirical cdf of X and F_Y is the empirical cdf of Y.
- Parameters
bin_edges (Tensor) – Tensor containing bin edges. The leading dimension must represent the N+1 bin edges.
cdf_x (Tensor) – Tensor containing a CDF one, defined over bins. The non-zeroth dimensions of bins and cdf must be compatible.
cdf_y (Tensor) – Tensor containing a CDF two, defined over bins. Must be compatible with cdf_x in terms of bins and shape.
- Returns
- Return type
The 1-Wasserstein distance between cdf_x and cdf_y
Tensor
- modulus.metrics.climate.acc.acc(pred: Tensor, target: Tensor, climatology: Tensor, lat: Tensor) → Tensor[source]
Calculates the Anomaly Correlation Coefficient
- Parameters
pred (Tensor) – […, H, W] Predicted tensor on a lat/long grid
target (Tensor) – […, H, W] Target tensor on a lat/long grid
climatology (Tensor) – […, H, W] climatology tensor
lat (Tensor) – [H] latitude tensor
- Returns
- Return type
ACC values for each field
Tensor
Note
- modulus.metrics.climate.efi.efi(bin_edges: Tensor, counts: Tensor, quantiles: Tensor) → Tensor[source]
Compute the Extreme Forecast Index for the given histogram.
The histogram is assumed to correspond with the given quantiles. That is, the bin midpoints must align with the quantiles.
- Parameters
bin_edges (Tensor) – The bin edges of the histogram over which the data distribution is defined. Assumed to be monotonically increasing but not evenly spaced.
counts (Tensor) – The counts of the histogram over which the data distributed is defined. Not assumed to be normalized.
quantiles (Tensor) – The quantiles of the climatological or reference distribution. The quantiles must match the midpoints of the histogram bins.
details. (See modulus/metrics/climate/efi for more) –
- modulus.metrics.climate.efi.efi_gaussian(pred_cdf: Tensor, bin_edges: Tensor, climatology_mean: Tensor, climatology_std: Tensor) → Tensor[source]
Calculates the Extreme Forecast Index (EFI) for an ensemble forecast against a climatological distribution.
- Parameters
pred_cdf (Tensor) – Cumulative distribution function of predictions of shape [N, …] where N is the number of bins. This cdf must be defined over the passed bin_edges.
bin_edges (Tensor) – Tensor of bin edges with shape [N+1, …] where N is the number of bins.
climatology_mean (Tensor) – Tensor of climatological mean with shape […]
climatology_std (Tensor) – Tensor of climatological std with shape […]
- Returns
- Return type
EFI values of each of the batched dimensions.
Tensor
Note
- modulus.metrics.climate.efi.normalized_entropy(pred_pdf: Tensor, bin_edges: Tensor, climatology_pdf: Tensor) → Tensor[source]
Calculates the relative entropy, or surprise, of using the prediction distribution with respect to the climatology distribution.
- Parameters
pred_cdf (Tensor) – Cumulative distribution function of predictions of shape [N, …] where N is the number of bins. This cdf must be defined over the passed bin_edges.
bin_edges (Tensor) – Tensor of bin edges with shape [N+1, …] where N is the number of bins.
climatology_pdf (Tensor) – Tensor of climatological probability function shape [N, …]
- Returns
- Return type
Relative Entropy values of each of the batched dimensions.
Tensor
- modulus.metrics.climate.reduction.global_mean(x: Tensor, lat: Tensor, keepdims: bool = False) → Tensor[source]
Computes global mean
This function computs the global mean of a lat/lon grid by weighting over the latitude direction and then averaging over longitude
- Parameters
x (Tensor) – The lat/lon tensor […, H, W] over which the mean will be computed
lat (Tensor) – A one-dimension tensor [H] representing the latitudes at which the function will return weights for
keepdims (bool, optional) – Keep aggregated dimension, by default False
- Returns
- Return type
Global mean tensor
Tensor
- modulus.metrics.climate.reduction.global_var(x: Tensor, lat: Tensor, std: bool = False, keepdims: bool = False) → Tensor[source]
Computes global variance
This function computs the global variance of a lat/lon grid by weighting over the latitude direction and then averaging over longitude
- Parameters
x (Tensor) – The lat/lon tensor […, H, W] over which the variance will be computed
lat (Tensor) – A one-dimension tensor [H] representing the latitudes at which the function will return weights for
std (bool, optional) – Return global standard deviation, by default False
keepdims (bool, optional) – Keep aggregated dimension, by default False
- Returns
- Return type
Global variance tensor
Tensor
- modulus.metrics.climate.reduction.zonal_mean(x: Tensor, lat: Tensor, dim: int = -2, keepdims: bool = False) → Tensor[source]
Computes zonal mean, weighting over the latitude direction that is specified by dim
- Parameters
x (Tensor) – The tensor […, H, W] over which the mean will be computed
lat (Tensor) – A one-dimension tensor representing the latitudes at which the function will return weights for
dim (int, optional) – The int specifying which dimension of x the reduction will occur, by default -2
keepdims (bool, optional) – Keep aggregated dimension, by default False
- Returns
- Return type
Zonal mean tensor of x over the latitude dimension
Tensor
- modulus.metrics.climate.reduction.zonal_var(x: Tensor, lat: Tensor, std: bool = False, dim: int = -2, keepdims: bool = False) → Tensor[source]
Computes zonal variance, weighting over the latitude direction
- Parameters
x (Tensor) – The tensor […, H, W] over which the variance will be computed
lat (Tensor) – A one-dimension tensor [H] representing the latitudes at which the function will return weights for
std (bool, optional) – Return zonal standard deviation, by default False
dim (int, optional) – The int specifying which dimension of x the reduction will occur, by default -2
keepdims (bool, optional) – Keep aggregated dimension, by default False
- Returns
- Return type
The variance (or standard deviation) of x over the latitude dimension
Tensor