Skip to content

Instantly share code, notes, and snippets.

welch / predict.juttle
Last active October 20, 2015 21:13
predict: return the unsurprising portion of a metric stream by estimating trend and seasonal effects
// Predict:
// Trend, seasonality, and noise estimation for metric streams.
// Predict is a sub which consumes a metric stream and emits a
// prediction stream based on estimated trend, seasonality, and a
// smoothed version of the input. Prediction errors (the difference
// between predict's output and the input) can signal anomalies in the
// stream.
// usage: predict [options]
welch /
Last active October 7, 2015 19:54
ingredients for the predict proc, in juttle

The juttle predict proc combines trend, seasonal, and level prediction. Although it is native javascript, many of its components can also be written in juttle, and those examples are here.

welch / cust-info.json
Last active September 28, 2015 19:41
customer info for join -table examples
{"time":"2016-01-01T00:00:00.000Z", "cust_id":1, "email":""},
{"time":"2016-01-01T00:00:02.000Z", "cust_id":2, "email":""},
{"time":"2016-01-01T00:00:03.000Z", "cust_id":3, "email":""}
welch / add-streams.juttle
Created September 28, 2015 18:18
example of collectd ingest in which several metrics are combined
// example of ingesting multiple metrics at a regular 20s pulse from
// collectd (timestamps are aligned across streams, simulated here),
// and merging them onto a single point so relative percentages can be computed.
// Useful patterns in add_streams:
// put *name = value applied to points having {name=foo, value=bar} layout,
// gives the values unique names in preparation for joining
// use of single-stream join to combine a variable number of input streams
// reduce -groupby by, which is the same as reduce by, but is convenient inside a sub.
// reduce time=first(time) gives reducer results same timestamp as their inputs
welch / random-demo.juttle
Created September 23, 2015 22:59
demo basic stdlib.random functions
// stdlib.random demos:
import "random.juttle" as random;
export sub poissonHisto() {
// render draws from 3 poisson distributions as a scatter chart.
// see
emit -limit 10000 -from 0
| put lambda_1=random.poisson(1), lambda_4=random.poisson(4), lambda_10=random.poisson(10)
| split lambda_1, lambda_4, lambda_10
welch / cpuZ-demo.juttle
Created September 23, 2015 22:43
cpuZ: visualize z-scores for a cpu metric.
// stats demos: statistics 101 for juttle data flows
// Each of the stream standardization approaches offered in stats is
// appropriate in a different setting. The demos here show some good
// and some bad choices.
import "stats.juttle" as stats;
// cpuZ: visualize z-scores for a cpu metric.
welch / alert-context.juttle
Last active October 1, 2015 01:24
annotate an alert event with recent lines from a logging stream
// Alerting with context:
// This example shows how to annotate an alert event with recent lines from
// a logging stream, to give context for the alert. This is accomplished with
// a custom reducer that tails the log stream, and a join of the current tail
// against each alert event as it occurs.
// The log-tailing stream is joined using the -table option, which means the
// join will fire only when the alert stream gets a new point, but not fire
// when the log stream gets new points.
welch / extract.m
Last active August 27, 2015 23:03
function pairs = readzmax(FileName)
fileID = fopen(FileName);
% read the file data
vals = fileread(FileName);
% Convert to string
dstr = sprintf('%s',vals);
% keep only lens data
GLDstart = regexp(dstr, 'GENEARL LENS DATA:','end');
dstr = dstr(GLDstart+2:end);
welch /
Last active August 27, 2015 21:46
convert zemax pupil data to csv
#!/usr/bin/env python
""" convert zemax output to csv for matlab import
usage: filename.txt ...
reads each filename.txt, outputting filename.csv
sample input file: forPupilMapping_Prescription.txt
import sys
welch /
Created August 19, 2015 15:39
why does the second test fail?


The basic set, fed a steady stream of two groups; A group


emit -from -limit 10
| put T = Duration.seconds(time -
| ( put name = "A" ; put name = "B", T = -T)

| (