---
name: "sdisdimval_bwcomp"
section: "3hdf"
platform: "linux"
package: "libhdf4g-dev"
version: "4.0.2-6"
release: "Debian 2.0 (Hamm)"
platforms: ["linux"]
url: "https://new.carta.tech/sdisdimval_bwcomp"
---

# sdisdimval\_bwcomp(3hdf)

**#include \<mfhdf.h\>**

- **intn SDisdimval\_bwcomp(int32 dimid)**

  *dimid*\
   	**IN: dimension ID returned from SDgetdimid**

- **Purpose**

  **Get the backward compatibility of a dimension record.**

- **Return value**

  **Returns SD\_DIMVAL\_BW\_COMP (1) if backward compatible,**  **SD\_DIMVAL\_BW\_INCOMP (0) if incompatible, FAIL if error.**

- **Description**

  **SDisdimval\_bwcomp gets the backward compatibility of a dimension record.** **SDstart reads dimension records into memory. The backward compatiblity**  **of each dimesion is decided by the existance of the dimension**  **vdata of class "DimVal0.0" in the dimension vgroup for that dimension.**  **If "DimVal0.0" vdata doesn't exist in that dimension vgroup,** **it will be flagged as backwards incompatible. The compatibility** **can be changed by SDsetdimval\_comp() any time between SDstart and** **SDend.**

  **Unlimited dimension is always backward compatible.**

- **Examples**

  ```
  status = SDisdimval_bwcomp(dimid1);
  if (status == SD_DIMVAL_BW_COMP)
      status = SDsetdimval_comp(dimid, SD_DIMVAL_BW_INCOMP);
  ```

- **FORTRAN**

  **integer function sfisdmvc(sdsid)**\
   **integer sdsid**\

- **See Also**

  **SDsetdimval\_comp(3)**