benkamphaus

benkamphaus

(require '[datomic.api :as d])

;; for a particular entity, find it's entire tx history
(defn e->tx-history [db ent-id]
  (->> (d/datoms (d/history db) :eavt ent-id)
       (map (fn [[e a v tx assert]]
              [e
               (-> db (d/pull '[:db/ident] a) :db/ident)
               v
               tx

benkamphaus

# requires scipy and numpy:
# e.g., with:
# pip install scipy numpy
import sys
import scipy.io as sio
from numpy import savetxt

filein = sys.argv[1]
fileout = sys.argv[2]
arr_dict = sio.loadmat(filein)

benkamphaus

(defn narcissistic?
  "Returns true if n with m digits is equal to each digit in n to the
  m exponent."
  [n]
  (let [digits   (map #(Character/digit % 10) (str n))
        n-digits (count digits)
        exps     (map #(Math/pow % n-digits) digits)]
    (== n (apply + exps))))

(take 10 (filter narcissistic? (iterate inc 10)))

benkamphaus

import numpy as np
import skimage
from skimage.feature import greycomatrix, greycoprops

def glcm_image(img, measure="dissimilarity"):
    """TODO: allow different window sizes by parameterizing 3, 4. Also should
    parameterize direction vector [1] [0]"""
    texture = np.zeros_like(sub)

    # quadratic looping in python w/o vectorized routine, yuck!

benkamphaus

(ns datomic-manual-tests.not-unique
  (:require [datomic.api :as d]))

(def db-uri "datomic:mem://not-unique")
(d/create-database db-uri)
(def conn (d/connect db-uri))

(def schema
 [{:db/id (d/tempid :db.part/db)
   :db/ident :parent/child

benkamphaus

What is this gist?

This is just a snapshot of what a high throughput Datomic transactor config looks like (with credentials/region, etc. settings elided).

I do not recommend cargo culting these settings for lower throughput systems. In those cases you should prefer the defaults.

Please refer to the capacity planning docs for a more nuanced understanding.

Warnings out of the way, here is how to use these reference settings:

benkamphaus

(require '[datomic.api :as d])

(defn tx-maps [log start]
    (into [] (map #(into {} %) (d/tx-range log start nil))))

(defn txid-match? [uuid]
  (fn [tx-map]
    (= uuid (:id tx-map))))

(defn lookup-tx [log uuid-val]

benkamphaus

(ns datomic-manual-tests.membership
  (:require [datomic.api :as d]))

(def db-uri "datomic:mem://memership")
(d/create-database db-uri)
(def conn (d/connect db-uri))

(def schema
 [{:db/id (d/tempid :db.part/db)
   :db/ident :person/name

benkamphaus

(ns datomic-manual-tests.with-bonanza
  (:require [datomic.api :as d]))

(def db-uri "datomic:mem://people")
(d/create-database db-uri)
(def conn (d/connect db-uri))

(def schema
 [{:db/id (d/tempid :db.part/db)
   :db/ident :person/age