Graphs, Tables and Captions My biased take on how to view your data - PowerPoint PPT Presentation

Graphs, Tables and Captions My biased take on how to view your data Aaron Schulman Featuring graphs from many talented artists Saturday, January 7, 12

Why do we graph? • To grasp lots of observations • To find patterns in observations • To see the distribution of observations • To determine the relationship between observations (be careful with correlation) • To find bugs in the experiment • To show others our observations Saturday, January 7, 12

A graph e p e n d e n t X - i n d p e n d e n t axis labels (and units) data Y - d e 2500 2000 power (mW) 1500 1000 500 0 0 2 4 6 8 10 time (s) Saturday, January 7, 12

A graph e p e n d e n t X - i n d p e n d e n t axis labels (and units) data Y - d e 2500 2000 power (mW) 1500 1000 500 0 0 2 4 6 8 10 time (s) Saturday, January 7, 12

A graph e p e n d e n t X - i n d p e n d e n t axis labels (and units) data Y - d e 2500 2000 power (mW) 1500 1000 500 0 0 2 4 6 8 10 time (s) Saturday, January 7, 12

A graph e p e n d e n t X - i n d p e n d e n t axis labels (and units) data Y - d e 2500 2000 power (mW) 1500 1000 500 0 0 2 4 6 8 10 time (s) Saturday, January 7, 12

Scatter plot Always view the raw data first 30 Fraction to BitTorrent’s download time 1 0.8 POP outdegree 20 0.6 0.4 10 0.2 PropShare y = 1.091x + 0.696 BitTyrant 0 0 0 5 10 15 20 0 10 20 30 Torrent ID, sorted by PropShare completion time Backbone routers in POP Fig. 11. POP outdegree vs backbone routers in the POP. A small random jitter jitter Figure 6: Runs on live swarms was added to the data points to expose their density. Circles represent the the median of at least ten nearby values: fewer medians are present for the the few large POPs. The solid line traces a linear regression fit, with R 2 = a 0 . 70 . This is an aggregate graph over nine ISPs, excluding Level3 due to with its logical mesh topology that gives POPs very high outdegree. E. Router Degree Distribution Credit: Neil Spring (left) Dave Levin (right) Saturday, January 7, 12

Bar graph Percentage (Average Battery) of Leaders, Bridges, and Clients 0.7 Leader Bridge 0.6 Client .389 .388 .395 0.5 Percentage of Nodes 0.4 .545 .578 .592 0.3 .690 .746 0.2 .736 0.1 0 130 227 306 Network Size Figure 5: Percentage of leaders, bridges, and clients in di ff erent topologies. The value on top of each bar denotes the average remaining battery for each case. Credit: Seungjoon Lee Saturday, January 7, 12

Distributions CDF Box and whisker 1.0 150 100 count 0.8 50 P ( POP size < x) 0 0.6 throughput (Mbit/s) 2 1.5 0.4 1 0.5 0.2 Fraction of POPs 0 Fraction of Routers -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 0.0 signal strength (dBm) 0 20 40 60 POP size (routers) Fig. 9. The cumulative distribution of POP sizes (solid), and the distribution of routers in POPs of different sizes (dotted). The mean POP size is 7.4 routers, and the median is 3 routers. Credit: Neil Spring Saturday, January 7, 12

Standard deviation and confidence interval Rel. error of miss. packet estimate 0.1 0.08 0.06 0.04 0.02 0 -0.02 -0.04 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Frac. non-beacon packets removed Know your data Saturday, January 7, 12

3D and heatmap IETF 2005 chan. 11 ple 10000 1 • 3D is not your 1000 0.8 friend Score 0.6 100 • Use a heatmap 0.4 10 0.2 0 1 0 10 20 30 40 50 Load (change in sequence number) Saturday, January 7, 12

Multiple axis and shared axis optimal first widest 1 fraction of naive energy 0.9 0.8 0.7 0 60 120 180 240 300 120 240 360 480 600 forced delay (s) prediction window (s) 18 18 LED1(G) On 16 16 Mean (3.05 mA) 14 14 12 12 Current(mA) 10 10 8 8 6 6 4 4 All LEDs On 2 2 Mean (6.30 mA) 0 0 0 0.5 1 1.5 0 0.5 1 1.5 Time(ms) Time(ms) Credit: Prabal Dutta (bottom) Saturday, January 7, 12

Watch out for grayscale 1 1 0.9 0.9 0.8 signal 0.8 signal 0.7 0.7 -50 -50 0.6 -60 0.6 -60 -70 0.5 -70 0.5 -80 -80 0.4 0.4 -90 -90 0.3 0.3 -100 -100 0.2 0.2 -110 -110 0.1 0.1 -120 -120 0 0 0 0.5 1 1.5 2 0 0.5 1 1.5 2 throughput (Mbit/s) Saturday, January 7, 12

Captions • Hypothesis or conclusion from the figure • Description the experiment • Description of the data points • Point out interesting ones • Give statistics • Explain outliers Saturday, January 7, 12

Credit: Lawrence Brakmo Saturday, January 7, 12

Saturday, January 7, 12

Packet Ignored Socket preemption interrupt buffer full ... device wireless wireless device kernel app driver card card driver Redundant Interference Out − of − range Access Point packets dropped Monitor Causes timing delays Causes missed packets Saturday, January 7, 12

Demo Saturday, January 7, 12

Graphing tools • Gnuplot - does everything, horrible defaults • matplotlib - python • Matlab, R - statistics , not flexible? • Jgraph - nice defaults , obscure • Excel - simple, horrible defaults, plot and data are one, not easy to script Saturday, January 7, 12

Why make a table • If you only have a few data points • If the interesting data is obvious • If you want to present a visual comparison Saturday, January 7, 12

Tables No extra bits Maintain Compatible Incremental Partial Packet Technique Protocol for correct packets link latency with 802.11 deployment Recovery Maranello X X X X X Checksum Seda [6] N/A X X FRJ [11] X X FEC ZipTx [14] X X PHY layer PPR [12] X X N/A X X X hints SOFT [27] N/A X X X MRD [20] Diversity SPaC [4] X N/A N/A X X X X X PRO [16] Table 1: Desired behavior and functionality of wireless error recovery protocols Parameter Value Hardware iPhone 3GS [1] Software SignalScope Pro [2] Function Signal Generator Output Headphones Type Tone Frequency 20 Hz to 24 kHz (5 kHz nom) Amplitude 0.00 dB Pan 0.000% Volume Maximum Table 1: Experiment parameters for determining the available power from the iPhone 3GS headset port. Saturday, January 7, 12

Deadlines & camera ready • Easiest to edit smallest to distribute • Script + data files EPS,PS PDF • You will have to make changes after submission • PDF Embedded fonts Saturday, January 7, 12