$countWomen = statistic('count', 'SD01', 1); // frequency women (1)
$countMen = statistic('count', 'SD01', 2); // frequency men (2)
$countDone = statistic('count', 'SD01'); // number of valid dates
$countAll = statistic('count', 'SD01', false, true); // All records
html('
So far in this survey '.$countAll.' Persons
have provided information about their gender, but the
interview was completed only in '.$countDone.' Cases.
The completed interviews include '.
$countWomen.' Women and '.
$countMen.' men.
');
question('SD01'); // Question about one's own gender
===== Frequency Count II =====
The ''%%'frequencies'%%'' statistic returns all possible values with one call.
**Note:** Note that the array only contains entries for the response codes whose responses are present at least once in the data set. Therefore, check whether the array key is present. This is possible, for example, with the ''??'' operator.
$freq = statistic('frequencies', 'SD01'); // frequencies
$numberWomen = ($freq[1] ?? 0);
$numberMen = ($freq[2] ?? 0);
html('
The completed interviews include '.
$numberWomen.' Women and '.
$numberMen.' men.
');
question('SD01'); // Question about one's own gender
===== Multivariate frequency =====
With the '''crosscount''' statistic, one can count (as in a crosstab) the cases where several variables apply.
Instead of a single variable, specify 2 or more variables as an array or separated by a comma ('',''). The third parameter ''//option//'' is used to specify which values are counted for each variable. Only cases are counted that have specified the first value for the first variable, the second value for the second variable, and so on.
$nYoungFemale = statistic('crosscount', 'SD01,SD02', '2,1'); // Variables and values as comma list ...
$nGrownFemale = statistic('crosscount', array('SD01','SD02'), array(2,2)); // ... or as arrays
html('
So far in this survey '.$nYoungFemale.' People
have indicated that they are female and in age group 1 (up to 18 years).
'.$nGrownFemale.' Females indicated an age of 19 years or older.
');
question('SD01'); // Question about one's own gender
question('SD02'); // Question about one's own age
===== Valid percent =====
The output is the share of a value in all valid entries. The third argument must be the value to be counted.
$proportionWomen = statistic('percent', 'SD01', 1); // proportion of women.
html('
So far in this survey '.
$proportionWomen.' Women participated.
');
question('SD01'); // Frage nach dem eigenen Geschlecht
===== Mode, most frequently specified value =====
Returns the value that has been selected most often so far. If multiple values have been selected equally often, then they are returned separated by a comma.
As a third argument (in this case of type Boolean) you can specify whether invalid values (no response, etc.) are also counted.
$modus = statistic('mode', 'AB01_02', true);
$modi = explode(',', $modus); // Separate multiple values
if (count($modi) > 1) {
// Several most frequently mentioned values
html('
Several answers were chosen equally often.
');
} else {
// Texts of the answer options (statistic() returns only the numeric code)
$text = getValuetext('AB01_02', $modus);
html('
The most common answer to this question was: '.$text.'.
');
}
===== Min, max and mean value of the valid entries =====
The statistics '''min''', '''mean''' and '''max''' will only calculate a correct value if numeric values are available for the question. In the case of a text entry, entries that are not numbers will be ignored -- unless it is specified as a third parameter (''true'') that invalid values should also be included in the statistics.
If there are no valid values so far, 0 is returned for '''mean''', for '''min''' and '''max''' the value ''false'' is returned.
$min = statistic('min', 'BB01_03');
$max = statistic('max', 'BB01_03');
$mean = statistic('mean', 'BB01_03');
html('
Participants have given the program an
Average rating of '.$mean.'
.
Ratings range from '.$min.' to '.$max.'
');
===== Evaluate partial data sets =====
By means of ''statistic('filter', ...)'' a filter can be set which will be applied to all further calls of ''statistic()''. As a second parameter (optional) //Variables// can be specified for acceleration, which are needed in subsequent calls.
The number of cases that match the filter is returned. The fourth parameter //AllData// only affects the return value, but not the further counting.
// Statistics on female participants only (SD02 = 1)
// The RT variables are loaded immediately to reduce latencies
$n = statistic('filter', array('RT02_01', 'RT02_02', 'RT02_03'), 'SD02==1');
// Mean of ratings (women only)
$mean1 = statistic('mean', 'RT02_01');
$mean2 = statistic('mean', 'RT02_02');
$mean3 = statistic('mean', 'RT02_03');
The filter allows common comparison operators (''>'', ''>='', ''<'', ''%%<=%%'', ''!='', ''==''), parentheses and and Boolean operators (''AND'', ''&&'', ''OR'', ''||'', ''NOT'', ''!'').
**Note:** Comparisons are only possible between one variable and a constant value (a number or a string) at a time, e.g. ''SD02==2'', comparisons between two variables (''SD03>SD04'') are not supported.
// Statistics only on female participants (SD02 = 1) aged 35 and over (SD03 >= 35).
$n = statistic('filter', false, '(SD02==1) AND (SD03 >= 35)');
Besides the variable names, ''QUESTNNR'', ''CASE'' and ''LANGUAGE'' can be used for the filter.
// Statistics only on female participants (SD02 = 1) aged 35 years and older (SD03 >= 35) in the German language version.
$n = statistic('filter', false, '(SD02==1) AND (SD03 >= 35) AND (LANGUAGE == "ger")');