diff --git a/examples/buffer_proto5.rs b/examples/buffer_proto5.rs
index c9ab08c..bb59fe3 100644
--- a/examples/buffer_proto5.rs
+++ b/examples/buffer_proto5.rs
@@ -4,12 +4,28 @@
 
 use coremem::{Driver, mat, meas, SpirvDriver};
 use coremem::geom::{region, Cube, Dilate, Memoize, Meters, Region, Spiral, SwapYZ, Torus, Translate, Wrap};
+use coremem::render::CsvRenderer;
 use coremem::stim::{CurlStimulus, Gated, Sinusoid1, TimeVarying1 as _};
+use coremem::sim::units::{Seconds, Frame, Time as _};
 use log::info;
 
 #[allow(unused)]
 use coremem::geom::{Coord as _, Region as _};
 
+/// Return just the extrema of some collection
+fn extrema(mut meas: Vec<f32>) -> Vec<f32> {
+    let mut i = 0;
+    while i + 2 < meas.len() {
+        let (prev, cur, next) = (meas[i], meas[i+1], meas[i+2]);
+        if (prev <= cur && cur <= next) || (prev >= cur && cur >= next) {
+            meas.remove(i+1);
+        } else {
+            i += 1;
+        }
+    }
+    meas
+}
+
 #[derive(Copy, Clone, Debug)]
 struct Params {
     feat_size: f32,
@@ -42,7 +58,17 @@ struct Params {
     dump_frames: Option<u64>,
 }
 
-fn run_sim(id: u32, p: Params) {
+#[derive(Clone, Debug)]
+struct Results {
+    m1: Vec<f32>,
+    m2: Vec<f32>,
+    h1: Vec<f32>,
+    h2: Vec<f32>,
+    iset1: Vec<f32>,
+    icoupling: Vec<f32>,
+}
+
+fn run_sim(id: u32, p: Params) -> Results {
     let m_to_um = |m: f32| (m * 1e6).round() as u32;
     let feat_vol = p.feat_size * p.feat_size * p.feat_size;
 
@@ -260,7 +286,7 @@ fn run_sim(id: u32, p: Params) {
     add_drive_square_pulse(&mut driver, &set1_region, p.set_duration + p.pre_time, p.clock_duration, peak_clock);
     // add_drive_step(&mut driver, &set1_region, set_duration + pre_time, peak_clock);
 
-    let duration = p.set_duration + p.pre_time + p.clock_duration + p.post_time;
+    let duration = Seconds(p.set_duration + p.pre_time + p.clock_duration + p.post_time).to_frame(driver.timestep()).round_up(32000);
 
     driver.add_measurement(meas::Volume::new("mem1", ferro1_region.clone()));
     driver.add_measurement(meas::MagneticLoop::new("mem1", ferro1_region.clone()));
@@ -277,9 +303,7 @@ fn run_sim(id: u32, p: Params) {
     driver.add_measurement(meas::Current::new("couplingtop", coupling_wire_top.clone()));
     driver.add_measurement(meas::Current::new("couplingbot", coupling_wire_bot.clone()));
 
-    return;
-
-    let prefix = format!("out/{}/{}-{}-{}setmA-{}setps-{}clkmA-{}clkps-{}um-{}:{}wraps",
+    let prefix = format!("out/{}/{}-{}-{}setmA-{}setps-{}clkmA-{}clkps-{}um-{}ferromaj-{}:{}wraps",
         base,
         base,
         *driver.size(),
@@ -288,6 +312,7 @@ fn run_sim(id: u32, p: Params) {
         (p.peak_clock_current * 1e3).round() as i64,
         (p.clock_duration * 1e12).round() as i64,
         (p.feat_size * 1e6).round() as i64,
+        p.ferro_major,
         p.wraps1,
         p.wraps2,
     );
@@ -295,10 +320,26 @@ fn run_sim(id: u32, p: Params) {
 
     driver.add_state_file(&*format!("{}/state.bc", prefix), 16000);
     driver.add_serializer_renderer(&*format!("{}/frame-", prefix), 32000, p.dump_frames);
-    driver.add_csv_renderer(&*format!("{}/meas.csv", prefix), 200, None);
-    driver.add_csv_renderer(&*format!("{}/meas-sparse.csv", prefix), 8000, None);
+    let meas_csv = format!("{}/meas.csv", prefix);
+    let meas_sparse_csv = format!("{}/meas-sparse.csv", prefix);
+    driver.add_csv_renderer(&*meas_csv, 200, None);
+    driver.add_csv_renderer(&*meas_sparse_csv, 8000, None);
 
     driver.step_until(duration);
+
+    let res = Results {
+        m1: extrema(CsvRenderer::new(&*meas_sparse_csv).read_column_as_f32("M(mem1)")),
+        m2: extrema(CsvRenderer::new(&*meas_sparse_csv).read_column_as_f32("M(mem2)")),
+        h1: extrema(CsvRenderer::new(&*meas_sparse_csv).read_column_as_f32("H(mem1)")),
+        h2: extrema(CsvRenderer::new(&*meas_sparse_csv).read_column_as_f32("H(mem2)")),
+        iset1: extrema(CsvRenderer::new(&*meas_sparse_csv).read_column_as_f32("I(set1)")),
+        icoupling: extrema(CsvRenderer::new(&*meas_sparse_csv).read_column_as_f32("Imag/cell(couplingtop)")),
+    };
+    std::fs::write(
+        format!("{}/results.txt", prefix),
+        format!("{:?}", res),
+    ).unwrap();
+    res
 }
 
 
diff --git a/src/driver.rs b/src/driver.rs
index 71a22a1..8c4c077 100644
--- a/src/driver.rs
+++ b/src/driver.rs
@@ -4,6 +4,7 @@ use crate::meas::{self, AbstractMeasurement};
 use crate::real::Real;
 use crate::render::{self, MultiRenderer, Renderer};
 use crate::sim::{GenericSim, MaterialSim, SampleableSim, SimState};
+use crate::sim::units::{Frame, Time};
 use crate::sim::spirv::SpirvSim;
 use crate::stim::AbstractStimulus;
 
@@ -31,7 +32,7 @@ pub struct Driver<S=SimState> {
     start_time: Instant,
     last_diag_time: Instant,
     /// simulation end time
-    sim_end_time: Option<f32>,
+    sim_end_time: Option<Frame>,
 }
 
 pub type SpirvDriver = Driver<SpirvSim>;
@@ -101,6 +102,9 @@ impl<S: SampleableSim> Driver<S> {
     pub fn size(&self) -> Index {
         self.state.size()
     }
+    pub fn timestep(&self) -> f32 {
+        self.state.timestep()
+    }
 }
 
 impl<S: SampleableSim + Send + Sync + 'static> Driver<S> {
@@ -204,7 +208,7 @@ impl<S: GenericSim + Clone + Default + Send + Sync + 'static> Driver<S> {
             let fps = (self.state.step_no() as f64) / overall_time;
             let sim_time = self.state.time() as f64;
             let percent_complete = match self.sim_end_time {
-                Some(t) => format!("[{:.1}%] ", 100.0 * self.state.time() / t),
+                Some(t) => format!("[{:.1}%] ", 100.0 * self.state.time() / *t.to_seconds(self.timestep())),
                 None => "".to_owned(),
             };
             info!(
@@ -233,9 +237,10 @@ impl<S: GenericSim + Clone + Default + Send + Sync + 'static> Driver<S> {
         self.step_multiple(1);
     }
 
-    pub fn step_until(&mut self, sim_end_time: f32) {
+    pub fn step_until<T: Time>(&mut self, sim_end_time: T) {
+        let sim_end_time = sim_end_time.to_frame(self.state.timestep());
         self.sim_end_time = Some(sim_end_time);
-        while self.dyn_state().time() < sim_end_time {
+        while self.dyn_state().step_no() < *sim_end_time {
             self.step_multiple(100);
         }
         // render the final frame
diff --git a/src/render.rs b/src/render.rs
index dc3c167..2ed780a 100644
--- a/src/render.rs
+++ b/src/render.rs
@@ -646,6 +646,17 @@ impl CsvRenderer {
             state: Mutex::new(Some(CsvState::Reading(reader))),
         }
     }
+    pub fn read_column(self, header: &str) -> Vec<String> {
+        let mut rd = match self.state.into_inner().unwrap() {
+            Some(CsvState::Reading(rd)) => rd,
+            _ => panic!("not reading!"),
+        };
+        let colno = rd.headers().unwrap().iter().position(|it| it == header).unwrap();
+        rd.into_records().map(|items| items.unwrap().get(colno).unwrap().to_owned()).collect()
+    }
+    pub fn read_column_as_f32(self, header: &str) -> Vec<f32> {
+        self.read_column(header).into_iter().map(|s| s.parse().unwrap()).collect()
+    }
 }
 
 impl<S: SampleableSim> Renderer<S> for CsvRenderer {
diff --git a/src/sim/mod.rs b/src/sim/mod.rs
index c4485b0..2b3ed6a 100644
--- a/src/sim/mod.rs
+++ b/src/sim/mod.rs
@@ -10,6 +10,7 @@ use std::convert::From;
 use std::iter::Sum;
 
 pub mod spirv;
+pub mod units;
 
 pub type StaticSim = SimState<R32, mat::Static<R32>>;
 
diff --git a/src/sim/units.rs b/src/sim/units.rs
new file mode 100644
index 0000000..5363f0e
--- /dev/null
+++ b/src/sim/units.rs
@@ -0,0 +1,54 @@
+use std::ops::Deref;
+
+pub trait Time {
+    fn to_frame(&self, time_step: f32) -> Frame;
+    fn to_seconds(&self, time_step: f32) -> Seconds;
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
+pub struct Frame(pub u64);
+
+impl Time for Frame {
+    fn to_frame(&self, _: f32) -> Frame {
+        *self
+    }
+    fn to_seconds(&self, time_step: f32) -> Seconds {
+        Seconds((**self as f32) * time_step)
+    }
+}
+
+impl Deref for Frame {
+    type Target = u64;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl Frame {
+    pub fn round_up(&self, div: u64) -> Frame {
+        let rem = self.0 % div;
+        match self.0 % div {
+            0 => *self,
+            rem => Frame(self.0 + div - rem),
+        }
+    }
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, PartialOrd)]
+pub struct Seconds(pub f32);
+
+impl Time for Seconds {
+    fn to_frame(&self, time_step: f32) -> Frame {
+        Frame((**self / time_step).round() as u64)
+    }
+    fn to_seconds(&self, _: f32) -> Seconds {
+        *self
+    }
+}
+
+impl Deref for Seconds {
+    type Target = f32;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}