HW Chi-Square
Compute a chi-square statistic comparing observed genotype counts against Hardy-Weinberg expectations derived from an allele frequency.
Description
Compute a chi-square statistic comparing observed genotype counts against Hardy-Weinberg expectations derived from an allele frequency.
HW Chi-Square is a focused biology tool that compute a chi-square statistic comparing observed genotype counts against Hardy-Weinberg expectations derived from an allele frequency. It calculates locally from the values you enter and exposes the result without changing the source observations.1
When to use HW Chi-Square
Use HW Chi-Square when you need to compute a chi-square statistic comparing observed genotype counts against Hardy-Weinberg expectations derived from an allele frequency. Enter Observed AA, Observed Aa, Observed aa, and Allele frequency p using the definitions and units below so the result can be reproduced.
- Observed AA
- An integer count or setting greater than or equal to 0.
- Observed Aa
- An integer count or setting greater than or equal to 0.
- Observed aa
- An integer count or setting greater than or equal to 0.
- Allele frequency p
- A finite measured or assumed value from 0 through 1.
How HW Chi-Square calculates the result
The published tool contract uses this rule: Compute a chi-square statistic comparing observed genotype counts against Hardy-Weinberg expectations derived from an allele frequency.1
- Chi-square
- The calculated chi-square.
Limitations of HW Chi-Square
The calculation does not propagate measurement uncertainty, sampling error, or biological and chemical variability. Allele frequency p must remain between 0 and 1.
Alternative or Complementary measurements
Retain the original Observed AA, Observed Aa, Observed aa, and Allele frequency p values and their units alongside the result. Genotype Frequencies is useful when you instead need to compute expected Hardy-Weinberg genotype frequencies p^2, 2pq, and q^2 from an allele frequency. Allele Frequency p provides another view by helping you estimate dominant allele frequency p from genotype counts using p = (2*AA + Aa) / (2*total).
References
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Hardy–Weinberg principle — Wikipedia contributors
Similar or alternative tools
- Genotype Frequencies
Compute expected Hardy-Weinberg genotype frequencies p^2, 2pq, and q^2 from an allele frequency.
- Allele Frequency p
Estimate dominant allele frequency p from genotype counts using p = (2*AA + Aa) / (2*total).
- X-Linked Male Frequency
Compute the frequency of affected males for an X-linked recessive trait, equal to the recessive allele frequency q under Hardy-Weinberg assumptions.