Add rgsl-nlinear library to rust-GSL.

Cargo.toml

@@ -12,6 +12,7 @@ edition = "2021"
 
 [dependencies]
 sys = { path = "gsl-sys", package = "GSL-sys", version = "3.0.0" }
+sys_mfnlin = { path = "gslsys-mfnlin", package = "gslsys-mfnlin", version = "0.1.0" }
 paste = "1.0"
 
 [features]

examples/Cargo.toml

@@ -113,6 +113,10 @@ name = "largefit"
 path = "./largefit.rs"
 required-features = ["GSL/v2_2"]
 
+[[bin]]
+name = "multifit_nlinear"
+path = "./multifit_nlinear.rs"
+
 [[bin]]
 name = "rng"
 path = "./rng.rs"

examples/multifit_nlinear.rs

@@ -0,0 +1,88 @@
+extern crate rgsl;
+
+use rgsl::gsl_multifit_nlinear_basic;
+use rgsl::gsl_multifit_nlinear_basic_df;
+
+use rgsl::types::rng::Rng;
+use rgsl::types::rng::RngType;
+
+
+#[no_mangle]
+fn expb_f(params: Vec<f64>, t: f64, _args: Vec<f64>) -> f64 {
+
+    let a = params.get(0).unwrap();
+    let lambda = params.get(1).unwrap();
+    let b = params.get(2).unwrap();
+
+    a * f64::exp(-lambda * t) + b
+}
+
+#[no_mangle]
+fn expb_df_a(params: Vec<f64>, t: f64, _args: Vec<f64>) -> f64 {
+    let lambda = params.get(1).unwrap();
+    f64::exp(-lambda * t)
+}
+
+#[no_mangle]
+fn expb_df_lambda(params: Vec<f64>, t: f64, _args: Vec<f64>) -> f64 {
+    let a = params.get(0).unwrap();
+    let lambda = params.get(1).unwrap();
+    -t * a * f64::exp(-lambda * t)
+}
+
+#[no_mangle]
+fn expb_df_b(_params: Vec<f64>, _t: f64, _args: Vec<f64>) -> f64 {
+    1.0
+}
+
+fn main() {
+
+    let params_out = vec![1.0, 1.0, 0.0];
+    let mut ts = Vec::new();
+    let mut ys = Vec::new();
+    let args = vec![];
+    let expb_dfs = vec![expb_df_a, expb_df_lambda, expb_df_b];
+
+    let mut rng = Rng::new(RngType::default()).unwrap();
+
+    for i in 0..100 {
+
+        let rand_flt = rng.uniform();
+
+        let ti = (i as f64) * 3.0 / (100.0 - 1.0);
+        let yi = 1.0 + 5.0 * f64::exp(-1.5 * ti);
+        let si = 0.1 * yi;
+        let dy = si * rand_flt;
+
+        ts.push(ti);
+        ys.push(yi + dy);
+    }
+
+    let (params, parerr, status) = match unsafe {
+        gsl_multifit_nlinear_basic(expb_f, params_out.clone(), &ts, &ys, &args, 100)
+    } {
+        Ok(value) => value,
+        Err(_) => {
+            eprintln!("Error encountered during solve!");
+            return;
+        }
+    };
+
+    println!("{:?}", params);
+    println!("{:?}", parerr);
+    println!("{}", status);
+
+    let (params, parerr, status) = match unsafe {
+        gsl_multifit_nlinear_basic_df(expb_f, &expb_dfs, params_out.clone(), &ts, &ys, &args, 100)
+    } {
+        Ok(value) => value,
+        Err(_) => {
+            eprintln!("Error encountered during solve!");
+            return;
+        }
+    };
+
+    println!("{:?}", params);
+    println!("{:?}", parerr);
+    println!("{}", status);
+}

gslsys-mfnlin/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "gslsys-mfnlin"
+version = "0.1.0"
+edition = "2021"
+
+build = "build.rs"
+
+[dependencies]
+libc = "0.2"
+GSL-sys = { version = "3.0.0", path = "../gsl-sys" }
+
+[build-dependencies]
+pkg-config = "0.3"
+
+[lib]
+name = "gslsys_mfnlin"
+crate-type = ["dylib", "rlib"]

gslsys-mfnlin/build.rs

@@ -0,0 +1,16 @@
+extern crate pkg_config;
+
+fn main() {
+    if std::process::Command::new("pkg-config").output().is_err() {
+        println!("cargo:rustc-link-lib=gsl");
+        println!("cargo:rustc-link-lib=gslcblas");
+        return;
+    }
+
+    if pkg_config::probe_library("gsl").is_err() {
+        println!("cargo:rustc-link-lib=gsl");
+    }
+    if pkg_config::probe_library("gslcblas").is_err() {
+        println!("cargo:rustc-link-lib=gslcblas");
+    }
+}