SampleJstat

<apex:page controller="StatsDemo" docType="html-5.0" lightningStylesheets="true">
    <apex:includeScript value="{!$Resource.jStat}"/>

    <h1>Calculate</h1>

    <apex:form>
        <apex:pageBlock>
            <apex:pageBlockSection>
                <apex:input value="{!probability}" type="number" label="Probability" html-step="any" required="true"/><br></br>
                <apex:input value="{!alpha}" type="number" label="Alpha" html-step="any" required="true"/><br></br>
                <apex:input value="{!beta}" type="number" label="Beta" html-step="any" required="true"/><br></br>
                <!-- <apex:input value="{!A}" type="number" label="A"/><br></br>
                <apex:input value="{!B}" type="number" label="B"/><br></br> -->
                <br></br>
                <apex:commandButton onClick="calculateInv()" value="Calculate" id="theButton"/>
                Result:
                <span id="val">
                    <apex:outputText value="{0, number, 000,000.00}">
                        <apex:param value="{!result}" />
                    </apex:outputText>
                </span>
            </apex:pageBlockSection>
        </apex:pageBlock>
    </apex:form>
    
    <script>

        function calculateInv () { 
            // var something = '{!A}';
            // var bVar = '{!B}';

            // something = (something === undefined) ? 0 : something;
            // bVar = (bVar === undefined) ? 1 : bVar;

            let lowResult = jStat.beta.inv('{!probability}', '{!alpha}', '{!beta}');

            let lowResult = jStat.beta.inv(.05,10,2);

            let highResult = jStat.beta.inv(.95,10,2);

            console.log('lowResult');
            console.log(lowResult);

            console.log('highResult');
            console.log(highResult);

            //Set the result variable
            document.getElementById('val').innerHTML = result;
        }
    </script>



</apex:page>