From c4cfcf15398578a016618d408f492295a914ce6a Mon Sep 17 00:00:00 2001
From: Laurent Mazare <laurent.mazare@gmail.com>
Date: Sat, 16 Dec 2023 18:11:36 -0600
Subject: [PATCH] Tweak the readme for phi and the default sample length.
 (#1450)

---
 candle-examples/examples/phi/README.md | 25 +++++++++++--------------
 candle-examples/examples/phi/main.rs   |  2 +-
 2 files changed, 12 insertions(+), 15 deletions(-)

diff --git a/candle-examples/examples/phi/README.md b/candle-examples/examples/phi/README.md
index 33665dba..70af6650 100644
--- a/candle-examples/examples/phi/README.md
+++ b/candle-examples/examples/phi/README.md
@@ -12,22 +12,19 @@ quantized variant.
 
 For the v2 version.
 ```bash
-$ cargo run --example phi --release -- --prompt "def print_prime(n): " --model 2
-def print_prime(n):
-    if n <= 1:
-        print("Not a prime number")
-    else:
-        for i in range(2, int(n**0.5)+1):
-            if (n % i) == 0:
-                print("Not a prime number")
-                break
-        else:
-            print("Prime number")
+$ cargo run --example phi --release -- --model 2 \
+  --prompt "A skier slides down a frictionless slope of height 40m and length 80m. What's the skier speed at the bottom?"
 
+A skier slides down a frictionless slope of height 40m and length 80m. What's the skier speed at the bottom?
 
-# Driver code
-n = 17
-print_prime(n)
+Solution:
+The potential energy of the skier is converted into kinetic energy as it slides down the slope. The formula for potential energy is mgh, where m is mass, g is acceleration due to gravity (9.8 m/s^2), and h is height. Since there's no friction, all the potential energy is converted into kinetic energy at the bottom of the slope. The formula for kinetic energy is 1/2mv^2, where v is velocity. We can equate these two formulas:
+mgh = 1/2mv^2
+Solving for v, we get:
+v = sqrt(2gh)
+Substituting the given values, we get:
+v = sqrt(2*9.8*40) = 28 m/s
+Therefore, the skier speed at the bottom of the slope is 28 m/s.
 ```
 
 For the v1.5 version.
diff --git a/candle-examples/examples/phi/main.rs b/candle-examples/examples/phi/main.rs
index 321ea5de..52d453b5 100644
--- a/candle-examples/examples/phi/main.rs
+++ b/candle-examples/examples/phi/main.rs
@@ -160,7 +160,7 @@ struct Args {
     seed: u64,
 
     /// The length of the sample to generate (in tokens).
-    #[arg(long, short = 'n', default_value_t = 100)]
+    #[arg(long, short = 'n', default_value_t = 5000)]
     sample_len: usize,
 
     #[arg(long)]