[SalesForce] How do we convert a Lead into person accounts in apex

Take a look at the ConvertLead Operation. Specifically, the setDoNotCreateOpportunity method. Below is an example of how to convert a lead within Apex, without creating an opportunity.

public class LeadClass{
    public static void doConvert(Id leadId){

        Database.LeadConvert lc = new database.LeadConvert();
        lc.setLeadId(leadId);
        lc.setDoNotCreateOpportunity(True); //**IMPORTANT METHOD HERE**

        LeadStatus convertStatus = [SELECT Id, MasterLabel FROM LeadStatus WHERE IsConverted=true LIMIT 1];
        lc.setConvertedStatus(convertStatus.MasterLabel);
        Database.LeadConvertResult lcr = Database.convertLead(lc);
    }
}

From this answer at Salesforce Developer Forums, it appears that when Person Accounts are enabled in your Org you can make the Company on Lead optional and remove it from the page layout.

Do you have Person accounts enabled in your Salesforce org? You can only do this through Support, and the change is irreversible once enabled. I am currently testing this out for a perpective client in a developer org.

If you do not have Person accounts enabled, you will not be able to change the Company field on the lead layout to no longer be required. Once Person accounts are enabled, this requirement is relaxed and you can remove the "Required" flag on the necessary page layouts (or remove the field altogether if you really don't need it). With that no longer required, Leads without Company information will convert to Person accounts.

I remember being able to do this with an org where we had Person Accounts enabled for leads, but you need a different record type and page layout for the Person Accounts where the Company could be made optional. Which is recommended in the Salesforce Help for this.