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1.16.1
This class helps managing the partitions of possible outcomes into categories for applying chi-square tests. More...
Public Member Functions | |
| OutcomeCategoriesChi2 (double[] nbExp) | |
| Constructs an OutcomeCategoriesChi2 object using the array nbExp for the number of expected observations in each category. | |
| OutcomeCategoriesChi2 (double[] nbExp, int smin, int smax) | |
| Constructs an OutcomeCategoriesChi2 object using the given nbExp expected observations array. | |
| OutcomeCategoriesChi2 (double[] nbExp, int[] loc, int smin, int smax, int nbCat) | |
| Constructs an OutcomeCategoriesChi2 object. | |
| void | regroupCategories (double minExp) |
| Regroup categories as explained earlier, so that the expected number of observations in each category is at least minExp. | |
| String | toString () |
| Provides a report on the categories. | |
Public Attributes | |
| int | nbCategories |
| Total number of categories. | |
| int | smin |
| Minimum index for valid expected numbers in the array nbExp. | |
| int | smax |
| Maximum index for valid expected numbers in the array nbExp. | |
| double[] | nbExp |
| Expected number of observations for each category. | |
| int[] | loc |
| loc[i] gives the relocation of the category i in the nbExp array. | |
This class helps managing the partitions of possible outcomes into categories for applying chi-square tests.
It permits one to automatically regroup categories to make sure that the expected number of observations in each category is large enough. To use this facility, one must first construct an OutcomeCategoriesChi2 object by passing to the constructor the expected number of observations for each original category. Then, calling the method regroupCategories will regroup categories in a way that the expected number of observations in each category reaches a given threshold minExp. Experts in statistics recommend that minExp be always larger than or equal to 5 for the chi-square test to be valid. Thus, minExp = 10 is a safe value to use. After the call, nbExp gives the expected numbers in the new categories and loc[i] gives the relocation of category \(i\), for each \(i\). That is, loc[i] = j means that category \(i\) has been merged with category \(j\) because its original expected number was too small, and nbExp[i] has been added to nbExp[j] and then set to zero. In this case, all observations that previously belonged to category \(i\) are redirected to category \(j\). The variable nbCategories gives the final number of categories, smin contains the new index of the lowest category, and smax the new index of the highest category.
Definition at line 297 of file GofStat.java.
| umontreal.ssj.gof.GofStat.OutcomeCategoriesChi2.OutcomeCategoriesChi2 | ( | double[] | nbExp | ) |
Constructs an OutcomeCategoriesChi2 object using the array nbExp for the number of expected observations in each category.
The smin and smax fields are set to 0 and
\((n-1)\) respectively, where \(n\) is the length of array nbExp. The loc field is set such that loc[i]=i for each i. The field nbCategories is set to \(n\).
| nbExp | array of expected observations for each category |
Definition at line 334 of file GofStat.java.
| umontreal.ssj.gof.GofStat.OutcomeCategoriesChi2.OutcomeCategoriesChi2 | ( | double[] | nbExp, |
| int | smin, | ||
| int | smax ) |
Constructs an OutcomeCategoriesChi2 object using the given nbExp expected observations array.
Only the expected numbers from the smin to smax (inclusive) indices will be considered valid. The loc field is set such that loc[i]=i for each i in the interval [smin, smax]. All loc[i] for i \(\le\) smin are set to smin, and all loc[i] for i \(\ge\) smax are set to smax. The field nbCategories is set to (smax - smin + 1).
| nbExp | array of expected observations for each category |
| smin | Minimum index for valid expected number of observations |
| smax | Maximum index for valid expected number of observations |
Definition at line 358 of file GofStat.java.
| umontreal.ssj.gof.GofStat.OutcomeCategoriesChi2.OutcomeCategoriesChi2 | ( | double[] | nbExp, |
| int[] | loc, | ||
| int | smin, | ||
| int | smax, | ||
| int | nbCat ) |
Constructs an OutcomeCategoriesChi2 object.
The field nbCategories is set to nbCat.
| nbExp | array of expected observations for each category |
| smin | Minimum index for valid expected number of observations |
| smax | Maximum index for valid expected number of observations |
| loc | array for which loc[i] gives the relocation of the category i |
Definition at line 382 of file GofStat.java.
| void umontreal.ssj.gof.GofStat.OutcomeCategoriesChi2.regroupCategories | ( | double | minExp | ) |
Regroup categories as explained earlier, so that the expected number of observations in each category is at least minExp.
We usually choose minExp = 10.
| minExp | mininum number of expected observations in each category |
Definition at line 397 of file GofStat.java.
| String umontreal.ssj.gof.GofStat.OutcomeCategoriesChi2.toString | ( | ) |
Provides a report on the categories.
Definition at line 448 of file GofStat.java.
| int [] umontreal.ssj.gof.GofStat.OutcomeCategoriesChi2.loc |
loc[i] gives the relocation of the category i in the nbExp array.
Definition at line 322 of file GofStat.java.
| int umontreal.ssj.gof.GofStat.OutcomeCategoriesChi2.nbCategories |
Total number of categories.
Definition at line 302 of file GofStat.java.
| double [] umontreal.ssj.gof.GofStat.OutcomeCategoriesChi2.nbExp |
Expected number of observations for each category.
Definition at line 317 of file GofStat.java.
| int umontreal.ssj.gof.GofStat.OutcomeCategoriesChi2.smax |
Maximum index for valid expected numbers in the array nbExp.
Definition at line 312 of file GofStat.java.
| int umontreal.ssj.gof.GofStat.OutcomeCategoriesChi2.smin |
Minimum index for valid expected numbers in the array nbExp.
Definition at line 307 of file GofStat.java.
1.16.1