Tidy gnuplot interface

1 files changed, 47 insertions, 44 deletions

diff --git a/src/plot/gnuplot.rs b/src/plot/gnuplot.rs
index ea52a18..8bb5ac6 100644
--- a/src/plot/gnuplot.rs
+++ b/src/plot/gnuplot.rs
@@ -1,11 +1,36 @@
-use std::io;
-use std::io::Write;
+use std::io::{self, Write};
 use std::path::PathBuf;
-use std::process;
-use std::process::{Command, Stdio};
+use std::process::{self, Command, Stdio};
 
 pub struct Gnuplot;
 
+const GNUPLOT_COMMAND: &str = "gnuplot";
+const OUTPUT_FILE: &str = "data";
+
+fn create_gnuplot_process(path: &str, chunk_size: u32, start: usize, end: usize)
+        -> Result<process::Child, io::Error> {
+    Command::new(GNUPLOT_COMMAND)
+        .args(&[
+            "-e",
+            format!("states={}; start={}; end={}", chunk_size, start, end).as_ref(),
+            "-c",
+            path,
+        ])
+        .stdin(Stdio::piped())
+        .stdout(Stdio::piped())
+        .spawn()
+}
+
+fn write_data_file(path: &str, data: &[[f64; 6]]) -> Result<(), io::Error> {
+    let mut file = std::fs::File::create(OUTPUT_FILE)?;
+    for line in data {
+        file.write_fmt(format_args!(
+            "{}; {}; {}; {}; {}; {}\n",
+            line[0], line[1], line[2], line[3], line[4], line[5]
+        ))?;
+    }
+}
+
 impl Gnuplot {
     fn exec_plot(
         data: &[[f64; 6]],
@@ -14,59 +39,37 @@ impl Gnuplot {
         end: usize,
         script: &str,
     ) -> Result<process::Child, io::Error> {
-        let mut path = PathBuf::from("gnuplot");
-        path.push(script);
-        let mut file = std::fs::File::create("data").expect("could not create data file");
-        let process = Command::new("gnuplot")
-            .args(&[
-                "-e",
-                format!("states={}; start={}; end={}", chunk_size, start, end).as_ref(),
-                "-c",
-                path.to_str().unwrap_or(script),
-            ])
-            .stdin(process::Stdio::piped())
-            .stdout(Stdio::piped())
-            .spawn()
-            .expect("Failed to spawn child process");
+        let path: PathBuf = ["gnuplot/", script].iter().collect();
+        let path = path.to_str().unwrap_or(script);
 
-        //let stdin = process.stdin.as_mut().expect("Failed to open stdin");
-        for line in data {
-            let line = format!(
-                "{}; {}; {}; {}; {}; {}\n",
-                line[0], line[1], line[2], line[3], line[4], line[5]
-            );
-            file.write_all(line.as_bytes())
-                .expect("Failed to write to stdin");
-        }
-        Ok(process)
+        let process = create_gnuplot_process(path, chunk_size, start, end)?;
+        write_data_file(path, data).map(|_| process)
+    }
+}
+
+fn plot_with(data: &[[f64; 6]], chunk_size: u32, start: usize, end: usize, name: &str) {
+    match Gnuplot::exec_plot(data, chunk_size, start, end, name) {
+        Ok(mut process) => println!("opening gnuplot {:?}", process.wait()),
+        Err(err) => println!("failed to start gnuplot: {}", err),
     }
 }
 
 impl super::Graph for Gnuplot {
     fn plot3d(data: &[[f64; 6]], chunk_size: u32) {
         let iterations = data.len() / chunk_size as usize;
-        match Gnuplot::exec_plot(data, chunk_size, 1, iterations, "anim3d.plt") {
-            Ok(mut process) => println!("opening gnuplot {:?}", process.wait()),
-            Err(err) => println!("failed to start gnuplot: {}", err),
-        }
+        plot_with(data, chunk_size, 1, iterations, "anim3d.plt");
     }
+
     fn animate3d(data: &[[f64; 6]], chunk_size: u32, start: usize, end: usize) {
-        match Gnuplot::exec_plot(data, chunk_size, start, end, "anim3d.plt") {
-            Ok(mut process) => println!("opening gnuplot {:?}", process.wait()),
-            Err(err) => println!("failed to start gnuplot: {}", err),
-        }
+        plot_with(data, chunk_size, start, end, "anim3d.plt")
     }
+
     fn plot2d(data: &[[f64; 6]], chunk_size: u32) {
         let iterations = data.len() / chunk_size as usize;
-        match Gnuplot::exec_plot(data, chunk_size, 1, iterations, "anim2d.plt") {
-            Ok(mut process) => println!("opening gnuplot {:?}", process.wait()),
-            Err(err) => println!("failed to start gnuplot: {}", err),
-        }
+        plot_with(data, chunk_size, 1, iterations, "anim2d.plt")
     }
+
     fn animate2d(data: &[[f64; 6]], chunk_size: u32, start: usize, end: usize) {
-        match Gnuplot::exec_plot(data, chunk_size, start, end, "anim2d.plt") {
-            Ok(mut process) => println!("opening gnuplot {:?}", process.wait()),
-            Err(err) => println!("failed to start gnuplot: {}", err),
-        }
+        plot_with(data, chunk_size, start, end, "anim2d.plt")
     }
 }