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mizar/decimal_rounding_error.ipynb

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decimal_rounding_error.ipynb
{
"nbformat": 4,
"nbformat_minor": 0,
"metadata": {
"colab": {
"provenance": [],
"authorship_tag": "ABX9TyNCp5LyUD/auAjhlGQAAiib",
"include_colab_link": true
},
"kernelspec": {
"name": "python3",
"display_name": "Python 3"
},
"language_info": {
"name": "python"
}
},
"cells": [
{
"cell_type": "markdown",
"metadata": {
"id": "view-in-github",
"colab_type": "text"
},
"source": [
"<a href=\"https://colab.research.google.com/gist/mizar/9dcae32696a03a1a0012a758fc324cd7/decimal_rounding_error.ipynb\" target=\"_parent\"><img src=\"https://colab.research.google.com/assets/colab-badge.svg\" alt=\"Open In Colab\"/></a>"
]
},
{
"cell_type": "code",
"execution_count": 1,
"metadata": {
"colab": {
"base_uri": "https://localhost:8080/"
},
"id": "MxAl6kX9GGAN",
"outputId": "ff2f1d4d-e83a-41d3-fc5b-9c6efff8bb7d"
},
"outputs": [
{
"output_type": "stream",
"name": "stdout",
"text": [
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]
}
],
"source": [
"import random\n",
"import decimal\n",
"\n",
"prec28 = decimal.Context()\n",
"\n",
"for _ in range(100):\n",
" a, b = random.random(), random.random()\n",
" x = prec28.create_decimal_from_float(a) + prec28.create_decimal_from_float(b / 2**52)\n",
" print(f\"{x:<32} {(1/x)*x-1:<+10}\")\n"
]
},
{
"cell_type": "code",
"source": [
"import random\n",
"import decimal\n",
"\n",
"precl = decimal.Context(prec=1)\n",
"prec28 = decimal.Context()\n",
"\n",
"for _ in range(100):\n",
" a = random.random()\n",
" x = prec28.create_decimal(precl.create_decimal_from_float(a))\n",
" print(f\"{x:<32} {1/x*x-1:<+10}\")\n"
],
"metadata": {
"id": "WJMmXRvsL45T",
"outputId": "1fda43e5-6018-464f-e694-eedb0020bdeb",
"colab": {
"base_uri": "https://localhost:8080/"
}
},
"execution_count": 2,
"outputs": [
{
"output_type": "stream",
"name": "stdout",
"text": [
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]
}
]
},
{
"cell_type": "code",
"source": [
"import random\n",
"import decimal\n",
"\n",
"precl = decimal.Context(prec=3)\n",
"prec28 = decimal.Context()\n",
"\n",
"for i in range(100):\n",
" a = i / 100 + 1\n",
" x = prec28.create_decimal(precl.create_decimal_from_float(a))\n",
" print(f\"{x:<32} {1/x*x-1:<+10}\")\n"
],
"metadata": {
"id": "fkYjT6RDP4IJ",
"outputId": "17635c2d-215e-4a3e-e1f8-b5723518247c",
"colab": {
"base_uri": "https://localhost:8080/"
}
},
"execution_count": 3,
"outputs": [
{
"output_type": "stream",
"name": "stdout",
"text": [
"1 +0 \n",
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]
}
]
}
]
}
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