use runmat_builtins::{ComplexTensor, ResolveContext, Tensor, Type, Value};
use runmat_macros::runtime_builtin;
use crate::builtins::common::random_args::complex_tensor_into_value;
use crate::builtins::common::spec::{
BroadcastSemantics, BuiltinFusionSpec, BuiltinGpuSpec, ConstantStrategy, GpuOpKind,
ReductionNaN, ResidencyPolicy, ScalarType, ShapeRequirements,
};
use crate::builtins::math::reduction::integration_common::{
canonical_shape_complex, canonical_shape_tensor, default_dimension_from_shape, dim_product,
gather_host_value, integration_error, interval_width, is_dimension_candidate, is_scalar_like,
pad_shape_for_dim, parse_optional_dim, promote_real_value_to_gpu, spacing_from_value,
value_has_gpu_tensor, value_into_complex_tensor, SpacingSpec,
};
use crate::builtins::math::reduction::type_resolvers::reduce_numeric_type;
use crate::BuiltinResult;
const NAME: &str = "trapz";
fn trapz_type(args: &[Type], ctx: &ResolveContext) -> Type {
reduce_numeric_type(args, ctx)
}
#[runmat_macros::register_gpu_spec(builtin_path = "crate::builtins::math::reduction::trapz")]
pub const GPU_SPEC: BuiltinGpuSpec = BuiltinGpuSpec {
name: "trapz",
op_kind: GpuOpKind::Custom("trapezoidal-integral"),
supported_precisions: &[ScalarType::F32, ScalarType::F64],
broadcast: BroadcastSemantics::Matlab,
provider_hooks: &[],
constant_strategy: ConstantStrategy::InlineLiteral,
residency: ResidencyPolicy::NewHandle,
nan_mode: ReductionNaN::Include,
two_pass_threshold: None,
workgroup_size: None,
accepts_nan_mode: false,
notes: "GPU inputs currently gather to the host for trapezoidal integration and re-upload real-valued outputs so downstream code can remain device-resident.",
};
#[runmat_macros::register_fusion_spec(builtin_path = "crate::builtins::math::reduction::trapz")]
pub const FUSION_SPEC: BuiltinFusionSpec = BuiltinFusionSpec {
name: "trapz",
shape: ShapeRequirements::Any,
constant_strategy: ConstantStrategy::InlineLiteral,
elementwise: None,
reduction: None,
emits_nan: false,
notes: "Discrete integration currently lowers to the runtime implementation rather than fusion kernels.",
};
#[runtime_builtin(
name = "trapz",
category = "math/reduction",
summary = "Trapezoidal numerical integration of sampled data.",
keywords = "trapz,trapezoidal integration,numerical integration,gpu",
accel = "none",
type_resolver(trapz_type),
builtin_path = "crate::builtins::math::reduction::trapz"
)]
async fn trapz_builtin(first: Value, rest: Vec<Value>) -> BuiltinResult<Value> {
let parsed = parse_arguments(first, rest)?;
let wants_gpu_result = value_has_gpu_tensor(&parsed.y)
|| parsed
.spacing
.as_ref()
.map(value_has_gpu_tensor)
.unwrap_or(false);
let y_value = gather_host_value(parsed.y).await?;
let spacing_value = match parsed.spacing {
Some(value) => Some(gather_host_value(value).await?),
None => None,
};
let result = match y_value {
Value::Complex(_, _) | Value::ComplexTensor(_) => {
let tensor = value_into_complex_tensor(NAME, y_value)?;
let shape = canonical_shape_complex(&tensor);
let dim = parsed
.dim
.unwrap_or_else(|| default_dimension_from_shape(&shape));
let spacing = spacing_from_value(NAME, spacing_value.clone(), &shape, dim)?;
complex_tensor_into_value(trapz_complex_tensor(&tensor, &spacing, dim)?)
}
other => {
let tensor = crate::builtins::common::tensor::value_into_tensor_for(NAME, other)
.map_err(|err| integration_error(NAME, err))?;
let shape = canonical_shape_tensor(&tensor);
let dim = parsed
.dim
.unwrap_or_else(|| default_dimension_from_shape(&shape));
let spacing = spacing_from_value(NAME, spacing_value, &shape, dim)?;
crate::builtins::common::tensor::tensor_into_value(trapz_tensor(
&tensor, &spacing, dim,
)?)
}
};
if wants_gpu_result && !matches!(result, Value::Complex(_, _) | Value::ComplexTensor(_)) {
promote_real_value_to_gpu(NAME, result)
} else {
Ok(result)
}
}
struct ParsedTrapzArgs {
spacing: Option<Value>,
y: Value,
dim: Option<usize>,
}
fn parse_arguments(first: Value, rest: Vec<Value>) -> BuiltinResult<ParsedTrapzArgs> {
match rest.len() {
0 => Ok(ParsedTrapzArgs {
spacing: None,
y: first,
dim: None,
}),
1 => {
let second = rest.into_iter().next().expect("one arg");
if is_dimension_candidate(&second) && !is_scalar_like(&first) {
Ok(ParsedTrapzArgs {
spacing: None,
y: first,
dim: parse_optional_dim(NAME, &second)?,
})
} else {
Ok(ParsedTrapzArgs {
spacing: Some(first),
y: second,
dim: None,
})
}
}
2 => {
let mut iter = rest.into_iter();
let y = iter.next().expect("y arg");
let dim_arg = iter.next().expect("dim arg");
Ok(ParsedTrapzArgs {
spacing: Some(first),
y,
dim: parse_optional_dim(NAME, &dim_arg)?,
})
}
_ => Err(integration_error(NAME, "trapz: too many input arguments")),
}
}
pub(crate) fn trapz_tensor(
tensor: &Tensor,
spacing: &SpacingSpec,
dim: usize,
) -> BuiltinResult<Tensor> {
if dim == 0 {
return Err(integration_error(NAME, "trapz: dimension must be >= 1"));
}
let shape = pad_shape_for_dim(&canonical_shape_tensor(tensor), dim);
let dim_index = dim - 1;
let len_dim = shape[dim_index];
let stride_before = dim_product(&shape[..dim_index]);
let stride_after = dim_product(&shape[dim..]);
let block = stride_before * len_dim;
let mut output = vec![0.0f64; stride_before * stride_after];
if len_dim > 1 {
for after in 0..stride_after {
let base = after * block;
for before in 0..stride_before {
let mut acc = 0.0f64;
for k in 0..(len_dim - 1) {
let idx0 = base + before + k * stride_before;
let idx1 = idx0 + stride_before;
let width = interval_width(spacing, idx0, idx1, k);
acc += 0.5 * width * (tensor.data[idx0] + tensor.data[idx1]);
}
output[after * stride_before + before] = acc;
}
}
}
let mut out_shape = shape;
out_shape[dim_index] = 1;
Tensor::new(output, out_shape).map_err(|err| integration_error(NAME, format!("trapz: {err}")))
}
fn trapz_complex_tensor(
tensor: &ComplexTensor,
spacing: &SpacingSpec,
dim: usize,
) -> BuiltinResult<ComplexTensor> {
if dim == 0 {
return Err(integration_error(NAME, "trapz: dimension must be >= 1"));
}
let shape = pad_shape_for_dim(&canonical_shape_complex(tensor), dim);
let dim_index = dim - 1;
let len_dim = shape[dim_index];
let stride_before = dim_product(&shape[..dim_index]);
let stride_after = dim_product(&shape[dim..]);
let block = stride_before * len_dim;
let mut output = vec![(0.0f64, 0.0f64); stride_before * stride_after];
if len_dim > 1 {
for after in 0..stride_after {
let base = after * block;
for before in 0..stride_before {
let mut acc = (0.0f64, 0.0f64);
for k in 0..(len_dim - 1) {
let idx0 = base + before + k * stride_before;
let idx1 = idx0 + stride_before;
let width = interval_width(spacing, idx0, idx1, k);
let (re0, im0) = tensor.data[idx0];
let (re1, im1) = tensor.data[idx1];
acc.0 += 0.5 * width * (re0 + re1);
acc.1 += 0.5 * width * (im0 + im1);
}
output[after * stride_before + before] = acc;
}
}
}
let mut out_shape = shape;
out_shape[dim_index] = 1;
ComplexTensor::new(output, out_shape)
.map_err(|err| integration_error(NAME, format!("trapz: {err}")))
}
#[cfg(test)]
pub(crate) mod tests {
use super::*;
use crate::builtins::common::test_support;
use futures::executor::block_on;
use runmat_accelerate_api::HostTensorView;
use runmat_builtins::{IntValue, LiteralValue};
fn run_trapz(first: Value, rest: Vec<Value>) -> BuiltinResult<Value> {
block_on(super::trapz_builtin(first, rest))
}
#[test]
fn trapz_type_reduces_default_dimension() {
let out = trapz_type(
&[Type::Tensor {
shape: Some(vec![Some(3), Some(4)]),
}],
&ResolveContext::new(Vec::new()),
);
assert_eq!(
out,
Type::Tensor {
shape: Some(vec![Some(1), Some(4)])
}
);
}
#[test]
fn trapz_scalar_is_zero() {
let value = run_trapz(Value::Num(5.0), Vec::new()).expect("trapz");
assert_eq!(value, Value::Num(0.0));
}
#[test]
fn trapz_row_vector_unit_spacing() {
let y = Tensor::new(vec![1.0, 2.0, 3.0], vec![1, 3]).unwrap();
let value = run_trapz(Value::Tensor(y), Vec::new()).expect("trapz");
assert_eq!(value, Value::Num(4.0));
}
#[test]
fn trapz_nonuniform_x_vector() {
let x = Tensor::new(vec![0.0, 1.0, 3.0], vec![1, 3]).unwrap();
let y = Tensor::new(vec![0.0, 1.0, 2.0], vec![1, 3]).unwrap();
let value = run_trapz(Value::Tensor(x), vec![Value::Tensor(y)]).expect("trapz");
assert_eq!(value, Value::Num(3.5));
}
#[test]
fn trapz_matrix_dimension_two() {
let y = Tensor::new(vec![1.0, 4.0, 2.0, 5.0, 3.0, 6.0], vec![2, 3]).unwrap();
let value = run_trapz(Value::Tensor(y), vec![Value::Int(IntValue::I32(2))]).expect("trapz");
let Value::Tensor(out) = value else {
panic!("expected tensor result");
};
assert_eq!(out.shape, vec![2, 1]);
assert_eq!(out.data, vec![4.0, 10.0]);
}
#[test]
fn trapz_complex_values() {
let y = ComplexTensor::new(vec![(1.0, 1.0), (2.0, 2.0), (3.0, 3.0)], vec![1, 3]).unwrap();
let value = run_trapz(Value::ComplexTensor(y), Vec::new()).expect("trapz");
assert_eq!(value, Value::Complex(4.0, 4.0));
}
#[test]
fn trapz_type_with_explicit_dim_keeps_rank() {
let ctx = ResolveContext::new(vec![LiteralValue::Unknown, LiteralValue::Number(2.0)]);
let out = trapz_type(
&[
Type::Tensor {
shape: Some(vec![Some(2), Some(3)]),
},
Type::Int,
],
&ctx,
);
assert_eq!(
out,
Type::Tensor {
shape: Some(vec![Some(2), Some(1)])
}
);
}
#[test]
fn trapz_gpu_input_reuploads_real_result() {
test_support::with_test_provider(|provider| {
let y = Tensor::new(vec![1.0, 2.0, 3.0], vec![1, 3]).unwrap();
let handle = provider
.upload(&HostTensorView {
data: &y.data,
shape: &y.shape,
})
.expect("upload");
let result = run_trapz(Value::GpuTensor(handle), Vec::new()).expect("trapz gpu");
let Value::GpuTensor(out) = result else {
panic!("expected gpu result");
};
let gathered = test_support::gather(Value::GpuTensor(out)).expect("gather");
assert_eq!(gathered.shape, vec![1, 1]);
assert_eq!(gathered.data, vec![4.0]);
});
}
}