diff --git a/README.md b/README.md
deleted file mode 100644
index c2f8760..0000000
--- a/README.md
+++ /dev/null
@@ -1,54 +0,0 @@
-# impatient
-
-A general purpose utility for estimating when a task will complete
-
-## Overview
-
-`impatient` is sort of like `pv` for tasks where you can't insert
-extra commands into a pipeline, and sort of like `progress` for tasks
-that aren't reading/writing a specific file on the local system.  If
-you give it any shell command that outputs a number (possibly with a
-K/M/G/T suffix), it will repeatedly run the command and show you how
-fast that number is changing.  If you give it the expected final value
-of the number, it'll also estimate how much longer you have to wait.
-It also has a specific option for tracking the total size of a
-file or directory as given by `du`.
-
-For example, here's `impatient` tracking an in-progress `zfs send` to
-a remote machine:
-
-```
-$ impatient -f "$(zfs list -pH -o used pool/home)" -c 'ssh remote-server zfs list -pH -o used remote-pool/backups/pool/home' -i 60
-109.8G - 2.8M/s - 263.7G total - 41.6% complete - 15h03m remaining - ETA 2021-11-23 11:34
-```
-
-Note that `-f` is given the value output by `zfs list`; we could
-give it a number directly, this just simplifies things in this
-particular scenario.  The `-p` flag for `zfs list` isn't strictly
-necessary, `impatient` can parse values like `50.7G`, but
-using the exact byte value provides more precision.
-
-`-c`, on the other hand, is given a quoted string containing a
-command, which will output the current progress value each time it's
-run. The command given to `-c` can be an arbitrary shell one-liner,
-use responsibly.
-
-## Usage
-
-```
-usage: impatient [-h] [-f FINAL] [-i INTERVAL] [-w WINDOW] (-p PATH | -c COMMAND)
-
-Display progress and time estimates for arbitrary tasks
-
-optional arguments:
-  -h, --help            show this help message and exit
-  -f FINAL, --final FINAL
-                        Expected final size/value at completion, optionally with a K/M/G/T suffix
-  -i INTERVAL, --interval INTERVAL
-                        Interval in seconds between samples (default 10)
-  -w WINDOW, --window WINDOW
-                        Number of samples to keep for the sliding window (default 100)
-  -p PATH, --path PATH  Track total disk usage of a given path
-  -c COMMAND, --command COMMAND
-                        Track value returned by a shell command; this should return a single number, optionally with a K/M/G/T suffix
-```
diff --git a/impatient b/impatient
index cad3eb1..20ac413 100755
--- a/impatient
+++ b/impatient
@@ -6,15 +6,16 @@ import subprocess
 import sys
 import time
 
+WINDOW_SIZE = 100
+
 SUFFIXES = 'KMGT'
 
 parser = argparse.ArgumentParser(description='Display progress and time estimates for arbitrary tasks')
-parser.add_argument('-f', '--final', type=str, help='Expected final size/value at completion, optionally with a K/M/G/T suffix')
+parser.add_argument('-f', '--final', type=str, help='Expected final size/value at completion.')
 parser.add_argument('-i', '--interval', type=int, default=10, help='Interval in seconds between samples (default 10)')
-parser.add_argument('-w', '--window', type=int, default=100, help='Number of samples to keep for the sliding window (default 100)')
 tracker_types = parser.add_mutually_exclusive_group(required=True)
 tracker_types.add_argument('-p', '--path', type=str, help='Track total disk usage of a given path')
-tracker_types.add_argument('-c', '--command', type=str, help='Track value returned by a shell command; this should return a single number, optionally with a K/M/G/T suffix')
+tracker_types.add_argument('-c', '--command', type=str, help='Track value returned by a shell command; this should return a single number, optionally followed by K/M/G/T')
 
 args = parser.parse_args()
 
@@ -22,9 +23,9 @@ def parse_value(v):
     suffix = v[-1].upper()
     if suffix in SUFFIXES:
         exponent = 3*(SUFFIXES.find(suffix)+1)
-        return float(v[:-1])*(10**exponent)
+        return int(v[:-1])*(10**exponent)
     else:
-        return float(v)
+        return int(v)
 
 def display_value(v):
     suffix = ''
@@ -66,8 +67,8 @@ while True:
     samples.append(current)
     if len(samples) < 2:
         continue
-    if len(samples) > args.window:
-        samples = samples[-args.window:]
+    if len(samples) > WINDOW_SIZE:
+        samples = samples[-WINDOW_SIZE:]
 
     rate = (current - samples[0])/((len(samples)-1)*args.interval)