# Matrix Folder/Forms Each Matrix has associated Folder/Forms. This page displays the Folder/Form combinations for the selected Matrix or Matrices. ## Single or Multiple Matrix selection You can display the Folder/Form combinations associated with a Matrix by selecting the Matrix in the list. Each Matrix is colored with a color automatically selected TrialGrid from the default color scheme, or a user-specified color. The default color scheme has 10 colors chosen to be easily distinguishable from each other. You can display Folder/Forms for a single Matrix or for multiple Matrices simultaneously by selecting 'Single' or 'Multiple'. When 'Multiple' has been selected you can select/deselect Matrices in the drop-down list of Matrices and 'Select All' or 'Deselect All'. A letter will be added to each Matrix when multiple Matrices are displayed. The letter for each Matrix is chosen by the system and is not user-configurable. ## Editing Matrix Folder/Forms When a single Matrix is selected you can add or remove Folder/Forms from that Matrix by clicking in the cell. ## Undo Changes to Matrix Folder/Forms can be undone before Saving by clicking on the Undo button. ## Names or OIDs selection You can display Folder and Form OIDs or Names in the row and column headers by clicking 'Names' or 'OIDs'. ## Hide empty rows/columns You can hide rows and columns which have no Folder/Forms for the currently selected Matrix/Matrices. This makes the displayed grid smaller which can be useful when working with very large Matrices. ## Filtering by Folders and/or Forms You can select one or more Folders and/or Forms from the dropdown lists to reduce the size of the displayed grid and display only the selected Folders and/or Forms. This can be useful when working with very large Matrices. ## Tooltips and navigation - Hovering over a Folder column header will display a tooltip with the Folder OID and Name. - Clicking on a Folder column header will open that Folder for editing. - Hovering over a Form row header will display a tooltip with the Form OID and Name. - Clicking on a Form row header will open that Form for editing. - Hovering over a Folder/Form cell will display the Folder and Form OIDs and Names and will display any Matrices which already include that Folder/Form. If Matrix Custom Properties are defined they will be displayed in the tooltip. - Hovering over the color for a Matrix in the Key will display the Matrix OID and Name. If Matrix Custom Properties are defined they will be displayed in the tooltip. - Clicking on a Matrix color in the Key will open that Matrix for editing.