Details
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Bug
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Status: Backlog
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Major - P3
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Resolution: Unresolved
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None
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None
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Server Tooling & Methods
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ALL
Description
assert.close() is used in our code both to compare for equality floating point numbers to a degree of precision and to integer values, evaluating only the X most significant digits. We should instead have separate functions for the 2. The current implementation can lead to surprising results when looking at it from only one use case:
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> assert.close(1, 2, '', 4)
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2019-01-04T16:26:47.030-0500 E QUERY [js] Error: 1 is not equal to 2 within 4 places, absolute error: 1, relative error: 0.5 :
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doassert@src/mongo/shell/assert.js:20:14
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assert.close@src/mongo/shell/assert.js:903:9
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@(shell):1:1
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>
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> // Result may be surprising to someone looking for a floating point precision check.
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> assert.close(100001, 100002, '', 4)
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> assert.close(0.01, 0.02, '', 4)
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2019-01-04T16:27:11.086-0500 E QUERY [js] Error: 0.01 is not equal to 0.02 within 4 places, absolute error: 0.01, relative error: 0.5 :
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doassert@src/mongo/shell/assert.js:20:14
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assert.close@src/mongo/shell/assert.js:903:9
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@(shell):1:1
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> assert.close(0.000001, 0.000002, '', 4)
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> // This fails a floating point precision check, but does not assert.
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> assert.close(2000000.1, 2000000.2, '', 4)
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>
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Attachments
Issue Links
- is related to
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SERVER-5044 $stdDev aggregation operator for standard deviation
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- Closed
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