add mag_squared

Cargo.toml

 [package]
 edition = "2021"
 name = "goertzel-nostd"
-version = "0.1.0"
+version = "0.2.0"
 authors = ["Stephen D"]
 repository = "https://github.com/mcpherrinm/goertzel.git"
 keywords = ["dsp", "goertzel", "fft", "fourier"]

src/lib.rs

@@ -49,6 +49,10 @@ impl Parameters {
 	pub fn mag(self, samples: &[f32]) -> f32 {
 		self.start().add_samples(samples).finish_mag()
 	}
+
+	pub fn mag_squared(self, samples: &[f32]) -> f32 {
+		self.start().add_samples(samples).finish_mag_squared()
+	}
 }
 
 impl Partial {
@@ -69,8 +73,12 @@ impl Partial {
 	}
 
 	pub fn finish_mag(self) -> f32 {
+		libm::sqrtf(self.finish_mag_squared())
+	}
+
+	pub fn finish_mag_squared(self) -> f32 {
 		let (real, imag) = self.finish();
-		libm::sqrtf(real * real + imag * imag)
+		real * real + imag * imag
 	}
 }